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Acer Predator Z271T With Tobii Eye Tracking
It seems like it's never been a better time to be a PC gamer. With new technologies like VR, AR, HDR, adaptive sync, and high refresh rates being introduced or improved upon at a rapid pace, there's always something new and exciting right around the corner.
Today, we're taking a look at one new technology that promises to bridge the gap between traditional monitors and full-blown VR or AR setups: eye tracking. Originally developed for its use as an assistive device for users with disabilities, eye tracking is making a big jump to gaming, as it can both provide an additional method of control input as well as alter the way the user experiences the game.
We first took a look at Tobii a few years ago with an early standalone eye tracking device. Now Tobii eye tracking is starting to make its way directly into monitors, and we spent some time with one such monitor: the Acer Predator Z271T.
Specs & Box Contents
The Acer Predator Z271T -- which I'll refer to as "Z27" going forward -- is a $700 27-inch monitor with a curved VA panel, 1920x1080 native resolution, and 144Hz refresh rate. The complete technical specifications:
|Acer Predator Z271T|
|Panel Technology||Vertical Alignment (VA)|
|Tilt Angle||-5 to +25 degrees|
|Viewing Angle||178 degrees horizontal/vertical|
|Maximum Adjustable Height||4.72 inches|
|Standard Refresh Rate||144 Hz|
|Color Supported||16.7 Million|
|Tearing Prevention Technology||G-SYNC|
|Speakers||2 x 7W|
|3.5mm Audio Output||Yes|
|USB 3.0||Yes (4-port hub)|
|Operating Power Consumption||27 watts|
|Standby Power Consumption||500 mW|
|Off-Mode Power Consumption||400 mW|
|Physical Characteristics (with stand)|
|VESA Mount Compatible||Yes (100mm x 100mm)|
|Package Contents||1 x DisplayPort cable
1 x HDMI cable
1 x USB 3.0 Cable
In terms of physical characteristics, the Z27 weighs in at 16.76lbs and is 20.4-inches high, 24.4-inches wide, and 10.6-inches deep when attached to its included stand. From the stand, the Z27 can tilt from -5 degrees to 25 degrees, and swivel up to 30 degrees side-to-side.
Introduction and Specifications
Acer's Predator Z850 takes the gaming monitor concept to the next level, projecting screen sizes up to 120" from less than two feet from a wall. It offers an ultra-wide 24:9 aspect ratio (at 1920x720), very high 3000 lumen brightness for gaming with ambient light (something projectors didn't used to be able to cope with), and a laser diode illumination system that lasts up to 30,000 hours. It's big, it's red, and you'd better believe it's expensive!
The first thing you need to know about the Predator Z850 is that it's an ultra short-thow projector. This means that unlike standard projectors that need the length of the room, or short-throw projectors that still need a few feet, the Predator Z850 can project a huge image from just inches from a wall. This is a relatively new thing for consumer projectors (unless you count the old rear projection TVs, which used the technology), and there are only a few models with ultra short throw (UST) ranging from the mainstram LG PF1000U, to the $50,000 4K Sony LSPX-W1S.
It's remarkable how UST changes how we think about projection, as the same depth taken up by the average TV table could provide an image larger than nearly any LCD television available, while being easily portable in the process. The Predator Z850 is all about flexibility, combining the inherent UST ability to project massive 120-inch images from less than two feet away, to built-in correction for various colors of wall paint (this could be used with a projection screen, too, of course). The only problem I can forsee as we continue is the price tag, which is $4999.
So how can we justify the price of the Z850? No matter how you slice it $5,000 is a lot of money, and the same investment could build an amazing multi-monitor setup as an alternative. But there really is something about turning an entire wall of your house into a display, and I had a lot of fun playing around with this projector (my wife was sorry it had to go back, as she enjoyed her 100-inch football games on the wall).
A unique combo of size and resolution
We see all kinds of monitors at PC Perspective; honestly it's probably too many. It's rare when a form factor or combination of features really feels unique, but today's review of the ASUS PB328Q is exactly that. Have we seen 2560x1440 displays? Countless. More than a few VA panels have graced our test benches. And 30-32 inch monitors were the biggest rage in screen technology as far back as 2007. A refresh rate of 75Hz is no longer as novel a feature as it used to be either.
The ASUS PB328Q combines all of that into a package that stands out from other professional, low cost monitor options. The largest 2560x1440 monitor that I have used previously is 27-inches, and the 5-in difference between that and what the PB328Q offers is an immediately obvious change. The question is though, does the size and resolution combination, along with the panel technology, combine to a form a product that is good for productivity, gaming, both, or neither? With a price of just $539 on Amazon, many users might be interested in the answer.
Here are the specifications for the ASUS PB328Q display.
|ASUS PB328Q Specifications|
|Screen Size||32 inch|
|Panel Technology||VA (vertical alignment)|
|Tilt Angle||-5 to +20 degrees|
|Standard Refresh Rate||75 Hz|
|Color Supported||1073.1M (10-bit) with 12-bit Look-up Table|
|Contrast Ratio||100,000,000:1 (ASCR)|
|Tearing Prevention Technology||None|
|Speakers||3W x 2 Stereo RMS|
|3.5mm Audio Output||Yes|
|Package Contents||Dual-link DVI cable
USB 3.0 cable
For those new to VA panel technology, is helps to have some background before we start testing the PB328Q. Vertical alignment panels are very good at blocking the backlight coming through the screen to the user's eyes, making them excellent at producing strong blacks and high contrast ratios when compared to other LCD technology. VA also results in vastly improved color reproduction and viewing angles, falling above TN and (usually) below IPS screens in that area.
UltraWide G-Sync Arrives
When NVIDIA first launched G-Sync monitors, they had the advantage of being first to literally everything. They had the first variable refresh rate technology, the first displays of any kind that supported it and the first ecosystem to enable it. AMD talked about FreeSync just a few months later, but it wasn't until March of 2015 that we got our hands on the first FreeSync enabled display, and it was very much behind the experience provided by G-Sync displays. That said, what we saw with that launch, and continue to see as time goes on, is that there are a much higher quantity of FreeSync options, with varying specifications and options, compared to what NVIDIA has built out.
This is important to note only because, as we look at the Acer Predator X34 monitor today, the first 34-in curved panel to support G-Sync, it comes 3 months after the release of the similarly matched monitor from Acer that worked with AMD FreeSync. The not-as-sexyily-named Acer XR341CK offers a 3440x1440 resolution, 34-in curved IPS panel and a 75Hz refresh rate.
But, as NVIDIA tends to do, they found a way to differentiate its own products, with the help of Acer. The Predator X34 monitor has a unique look and style to it, and it improves the maximum refresh rate to 100Hz (although that is considered overclocking). The price is a bit higher too, coming in at $1300 or so on Amazon.com; the FreeSync-enabled XR341CK monitor sells for just $941.
Another TN Option for FreeSync Fans
If you had asked me a year ago how many monitors we would be able to store in the PC Perspective offices, I would have vastly underestimated the true answer. It seems that not only is the demand from readers for information about the latest and greatest display technology at a demand that we have never seen, but vendors that sell high quality monitors for enthusiasts and gamers are pumping out more models than I can keep track of.
But this is good, right? The more options we have, the more likely we are to find the best choice for each user, for each budget and for each required feature set. But more choices can also lead to confusion - that's where we continue to chime in. Today we are taking a look at the ASUS MG278Q monitor, a 27-in 2560x1440 display with support for AMD FreeSync technology and sporting a maximum refresh rate of 144Hz. With a TN panel rather than IPS, the MG278Q has a current selling price of just $399, well under the equivalent G-Sync monitors.
Even better, since we started our evaluation on the display, AMD released the Radeon Crimson driver, introducing a new feature called Low Frame Rate Compensation. This essentially allows most of the FreeSync displays on the market to match NVIDIA G-Sync's ability to handle lower frame rates without resorting to V-Sync tearing, etc. If you haven't read about it, do so in the link above.
It's hard to believe that it has only been 14 months since the release of the first ASUS ROG Swift, the PG278Q, back in August of 2014. It seems like lifetimes have passed, with drama circling around other G-Sync panels, the first release of FreeSync screens, the second geneation of FreeSync panels that greatly improve overdrive. Now, we sit in the middle of the second full wave of G-Sync screens. A lot can happen in this field if you blink.
The PG278Q was easily the best G-Sync monitor on the market for quite a long time. It offered performance, features and quality that very few other monitors could match, and it did it all while including support for NVIDIA's G-Sync variable refresh rate technology. If you are new to VRR tech, and want to learn about G-Sync you can check out our original editorial or an in-depth interview with NVIDIA's Tom Petersen. In short: being able to have a variable refresh rate on a panel match the frame rate of the game prevents Vsync quirks like screen tearing and judder.
But a lot has changed since ASUS released the PG278Q including the release of other higher quality monitors from the likes of Acer, BenQ and others. ASUS showed off some new G-Sync ready displays at CES but that was way back in January of 2015 - more than 10 months ago! The PG279Q was the most interesting to us then and remains that way today. There are some impressive specifications on the table including a 27-in 2560x1440 screen built on IPS technology, to improve color reproduction and view angles, a 165Hz maximum refresh rate and the best build quality we have seen on a gaming monitor to date.
This time ASUS has a lot more competition to deal with but can the ROG Swift PG279Q real ignite ASUS as the best G-Sync monitor provider? What kind of experience do you get for a $799 monitor today?
Specs, Physical Design
Over the past 2 years or so we have noticed a trend in PC gaming: more and more gamers are realizing the importance of the display in the total gaming experience. Having been in the reviews game for nearly 16 years, I am just as guilty as most of you reading this of falling into the trap of "good enough" monitors. Steam surveys and our own data from readers shows that most of you have found some form of 1920x1080 screen and have stuck with it. But the truth is changing your monitor can and will dramatically impact how you game, how you work and just how impressed you feel each and every time you sit down in front of your PC.
Today we are looking at one of the monitors that promises to change how you view productivity and gaming. The Acer XR341CK continues the momentum of a new aspect ratio of monitors, 21:9. Otherwise known as UltraWide displays, they are available in both 2560x1080 and 3440x1440 resolutions, though our testing model today uses the latter, larger option. This Acer has a slight curve to it as well, just enough to be enjoyable without changing viewing angles for the primary user. With a 34 inch diagonal measurement, IPS panel technology and AMD FreeSync variable refresh rate support, the Acer XR341CK is likely to be our new favorite monitor for AMD Radeon users.
This doesn't come without a cost though: the XR341CK retails for just over $1,000 on Amazon. For many of you that will be a breath-taking price, and not in a good way. But consider the length of time that users tend keep monitors, I think we can make the case that type of investment is actually worthwhile.
Introduction, Specifications, and Packaging
We have reviewed a lot of Variable Refresh Rate displays over the past several years now, and for the most part, these displays have come with some form of price premium attached. Nvidia’s G-Sync tech requires an additional module that adds some cost to the parts list for those displays. AMD took a while to get their FreeSync tech pushed through the scaler makers, and with the added effort needed to implement these new parts, display makers naturally pushed the new features into their higher end displays first. Just look at the specs of these displays:
- ASUS PG278Q 27in TN 1440P 144Hz G-Sync
- Acer XB270H 27in TN 1080P 144Hz G-Sync
- Acer XB280HK 28in TN 4K 60Hz G-Sync
- Acer XB270HU 27in IPS 1440P 144Hz G-Sync
- LG 34UM67 34in IPS 25x18 21:9 48-75Hz FreeSync
- BenQ XL2730Z 27in TN 1440P 40-144Hz FreeSync
- Acer XG270HU 27in TN 1440P 40-144Hz FreeSync
- ASUS MG279Q 27in IPS 1440P 144Hz FreeSync (35-90Hz)
Most of the reviewed VRR panels are 1440P or higher, and the only 1080P display currently runs $500. This unfortunately leaves VRR technology at a price point that is simply out of reach of gamers unable to drop half a grand on a display. What we need was a good 1080P display with a *full* VRR range. Bonus points to high refresh rates and in the case of a FreeSync display, a minimum refresh rate low enough that a typical game will not run below it. This shouldn’t be too hard since 1080P is not that demanding on even lower cost hardware these days. Who was up to this challenge?
Nixeus has answered this call with their new Nixeus Vue display. This is a 24” 1080P 144Hz FreeSync display with a VRR bottom limit of 30 FPS. It comes in two models, distinguished by a trailing letter in the model. The NX-VUE24B contains a ‘base’ model stand with only tilt support, while the NX-VUE24A contains a ‘premium’ stand with full height, rotation, and tilt support.
Does the $330-350 dollar Nixues Vue 24" FreeSync monitor fit the bill?
Introduction and First Impressions
The ASUS PB258Q is a "frameless" monitor with a full 2560x1440 resolution from a fairly compact 25-inch size, and at first glance it might appear to be a bare LCD panel affixed to a stand. This attractive design also features 100% sRGB coverage and full height/tilt/swivel and rotation adjustment. The price? Less than $400. We'll put it to the test to see just what kind of value to expect here.
A beautiful looking monitor even with nothing on the display
The ASUS PB258Q came out of nowhere one day when I was looking to replace a smaller 1080p display on my desk. Given some pretty serious size constraints I was hesitant to move up to the 27 - 30 inch range for 2560x1440 monitors, but I didn't want to settle for 1920x1080 again. The ASUS PB258Q intrigued me immediately not only due to its interesting size/resolution of 25-inch/1440p, but also for the claimed 100% sRGB coverage and fully adjustable stand. And then I looked over at the price. $376.99 shipped from Amazon with Prime shipping? Done.
The pricing (and compact 25-inch size) made it a more compelling choice to me than the PB278Q, ASUS's "professional graphics monitor" which uses a PLS panel, though this larger display has recently dropped in price to the $400 range. When the PB258Q arrived a couple of days later I was first struck by how compact it is, and how nice the monitor looked without even being powered up.
A few years ago, we took our first look at the inexpensive 27" 1440p monitors which were starting to flood the market via eBay sellers located in Korea. These monitors proved to be immensely popular and largely credited for moving a large number of gamers past 1080p.
However, in the past few months we have seen a new trend from some of these same Korean monitor manufacturers. Just like the Seiki Pro SM40UNP 40" 4K display that we took a look at a few weeks ago, the new trend is large 4K monitors.
Built around a 42-in LG AH-IPS panel, the Wasabi Mango UHD420 is an impressive display. Inclusion of HDMI 2.0 and DisplayPort 1.2 allow you to achieve 4K at a full 60Hz and 4:4:4 color gamut. At a cost of just under $800 on Amazon, this is an incredibly appealing value.
Whether or not the UHD420 is a TV or a monitor is actually quite the tossup. The lack of a tuner
might initially lead you to believe it's not a TV. Inclusion of a DisplayPort connector, and USB 3.0 hub might make you believe it's a monitor, but it's bundled with a remote control (entirely in Korean). In reality, this display could really be used for either use case (unless you use OTA tuning), and really starts to blur the lines between a "dumb" TV and a monitor. You'll also find VESA 400x400mm mounting holes on this display for easy wall mounting.
We have been tracking the differences between AMD’s FreeSync and Nvidia’s G-Sync for some time now. The launch of FreeSync-capable displays started out a bit shaky, as some features we took for granted went missing. The first round of FreeSync displays we reviewed came with non-functional overdrive when the display / GPU pipeline was operating in FreeSync mode.
Comparison of overdrive response in first round FreeSync displays. Images should look like the ROG Swift (left), which was correctly applying overdrive.
While AMD apparently fixed a portion of this problem in a subsequent driver update, getting overdrive to function in these early displays would require a firmware update. Unlike what you may be used to with a motherboard or SSD firmware, displays are not typically end-user upgradeable. This meant that even if manufacturers produced a fix, owners would have to send in their display to be updated (and be without it for several weeks).
The only manufacturer to step forward and retroactively support overdrive in their first gen FreeSync panel was BenQ. In a statement issued via TFTCentral:
BenQ have confirmed that the FreeSync/AMA issue which affected their XL2730Z display has now been fixed. This issue caused the overdrive (AMA) feature to not function when the screen was connected to a FreeSync capable system. As a result, users could not make use of the AMA feature and benefit from the improved response times that the 'normal' AMA mode offered, as compared with AMA Off. See our review for more information.
A driver update from AMD is already available and should be downloaded from their website. In addition BenQ will be releasing a firmware update for the monitor itself to fix this issue. Current stocks in distribution are being recalled and updated with retailers so future purchases should already carry this new firmware. This is expected to apply for stock purchased AFTER 1st July, as V002 firmware screens should be shipped by BenQ to distributors in late June.
For those who already have an XL2730Z if you want to, you can return it to BenQ for them to carry out the firmware update for you. This only applies if the user is experiencing issues with the performance of the screen. There is no simple way for the end user to update the firmware themselves and it is not encouraged. Users should contact BenQ support through their relevant country website for more information on how to return their screen for the update.
The catch with the above is that the statement came from BenQ PR for Europe, and we nor TFTCentral have been able to confirm any equivalent upgrade process in place for the USA. We did note in various online reviews that those receiving their BenQ XL2730Z in the last week of June confirmed having the new V002 firmware.
If you have one of these panels, verifying your firmware is simple. Hold down the menu button while powering up the display (you will have to hold the power button for a few seconds before you hear a beep).
The display will power up and appear as normal, except that now pressing the menu button again will bring up the above service menu. Those with the update will have “V002” as the starting text of the ‘F/W Version’ result.
Overdrive functioning on the ASUS MG279Q IPS FreeSync display, showing an odd simultaneous ‘negative ghost’ outline of a slightly ghosted image.
We have been eager to retest the BenQ since hearing of this updated firmware revision. While we have seen overdrive functioning in the recent ASUS MG279Q, it was not a perfect implementation, and we were curious to know if BenQ’s implementation fared any better.
Introduction, Specifications, and Packaging
AMD fans have been patiently waiting for a proper FreeSync display to be released. The first round of displays using the Adaptive Sync variable refresh rate technology arrived with an ineffective or otherwise disabled overdrive feature, resulting in less than optimal pixel response times and overall visual quality, especially when operating in variable refresh rate modes. Meanwhile G-Sync users had overdrive functionality properly functioning , as well as a recently introduced 1440P IPS panel from Acer. The FreeSync camp was overdue for an IPS 1440P display superior to that first round of releases, hopefully with those overdrive issues corrected. Well it appears that ASUS, the makers of the ROG Swift, have just rectified that situation with a panel we can finally recommend to AMD users:
Before we get into the full review, here is a sampling of our recent display reviews from both sides of the camp:
- ASUS PG278Q 27in TN 1440P 144Hz G-Sync
- Acer XB270H 27in TN 1080P 144Hz G-Sync
- Acer XB280HK 28in TN 4K 60Hz G-Sync
- Acer XB270HU 27in IPS 1440P 144Hz G-Sync
- LG 34UM67 34in IPS 25x18 21:9 48-75Hz FreeSync
- BenQ XL2730Z 27in TN 1440P 40-144Hz FreeSync
- Acer XG270HU 27in TN 1440P 40-144Hz FreeSync
- ASUS MG279Q 27in IPS 1440P 144Hz FreeSync(35-90Hz) < You are here
The reason for there being no minimum rating on the G-Sync panels above is explained in our article 'Dissecting G-Sync and FreeSync - How the Technologies Differ', though the short version is that G-Sync can effectively remain in VRR down to <1 FPS regardless of the hardware minimum of the display panel itself.
Introduction and Specifications
Seiki has spent the past few years making quite the entrance into the display market. Starting with LCD TVs, they seemingly came out of nowhere back in April of 2013 with a 50” 4K display that was available at a very competitive price at that time. Since then, we’ve seen a few more display releases out of Seiki, and they were becoming popular among home theater enthusiasts on a budget and for gamers who wanted a bigger panel in front of them. Last June, Seiki announced a desktop line of 4K monitors. These would not just be repurposed televisions, but ground-up designs intended for desktop professionals and gamers alike. The most eagerly awaited part of this announcement was promised 60 Hz support at 4K resolutions.
Just under a year later, we are happy to bring you a review of the first iteration on this new Seiki Pro lineup:
Introduction and Specifications
Displays have been a hot item as of late here at PC Perspective. Today we are looking at the new Acer XB270HU. In short, this is an IPS version of the ASUS ROG Swift. For the long version, it is a 1440P, 144Hz, G-Sync enabled 27 inch display. This is the first G-Sync display released with an IPS panel, which is what makes this release such a big deal. Acer has been pushing hard on the display front, with recent releases of the following variable refresh capable displays:
- XB270H 27in 1080P 144Hz G-Sync
- XB280HK 28in 4K 60Hz G-SYnc
- XG270HU 27in 1440P 40-144Hz FreeSync
- XB270HU 27in 1440P 144Hz G-Sync < you are here
The last entry in that list is the subject of todays review, and it should look familiar to those who have been tracking Acer's previous G-Sync display releases:
Here's our video overview of this new display. I encourage you to flip through the review as there are more comparison pictures and information to go along.
A monitor for those that like it long
It takes a lot to really impress someone that sits in front of dual 2560x1600 30-in IPS screens all day, but the LG 34UM95 did just that. With a 34-in diagonal 3440x1440 resolution panel forming a 21:9 aspect ratio, built on LG IPS technology for flawless viewing angles, this monitor creates a work and gaming experience that is basically unmatched in today's market. Whether you need to open up a half-dozen Excel or Word documents, keep an eye on your Twitter feed while looking at 12 browsers or run games at near Eyefinity/Surround levels without bezels, the LG 34UM95 is a perfect option.
Originally priced north of $1200, the 34UM95 and many in LG's 21:9 lineup have dropped in price considerably, giving them more avenues into users' homes. There are obvious gaming advantages to the 34-in display compared to a pair of 1920x1080 panels (no bezel, 20% more pixels) but if you have a pair of 2560x1440 screens you are going to be giving up a bit. Some games might not handle 21:9 resolutions well either, just as we continue to see Eyefinity/Surround unsupported occasionally.
Productivity users will immediately see an improvement, both for those us inundated with spreadsheets, web pages and text documents as well as the more creative types with Adobe Premiere timelines. I know that Ken would definitely have approved us keeping this monitor here at the office for his use.
Check out the video above for more thoughts on the LG 34UM95!
What is FreeSync?
FreeSync: What began as merely a term for AMD’s plans to counter NVIDIA’s launch of G-Sync (and mocking play on NVIDIA’s trade name) has finally come to fruition, keeping the name - and the attitude. As we have discussed, AMD’s Mantle API was crucial to pushing the industry in the correct and necessary direction for lower level APIs, though NVIDIA’s G-Sync deserves the same credit for recognizing and imparting the necessity of a move to a variable refresh display technology. Variable refresh displays can fundamentally change the way that PC gaming looks and feels when they are built correctly and implemented with care, and we have seen that time and time again with many different G-Sync enabled monitors at our offices. It might finally be time to make the same claims about FreeSync.
But what exactly is FreeSync? AMD has been discussing it since CES in early 2014, claiming that they would bypass the idea of a custom module that needs to be used by a monitor to support VRR, and instead go the route of open standards using a modification to DisplayPort 1.2a from VESA. FreeSync is based on AdaptiveSync, an optional portion of the DP standard that enables a variable refresh rate courtesy of expanding the vBlank timings of a display, and it also provides a way to updating EDID (display ID information) to facilitate communication of these settings to the graphics card. FreeSync itself is simply the AMD brand for this implementation, combining the monitors with correctly implemented drivers and GPUs that support the variable refresh technology.
A set of three new FreeSync monitors from Acer, LG and BenQ.
Fundamentally, FreeSync works in a very similar fashion to G-Sync, utilizing the idea of the vBlank timings of a monitor to change how and when it updates the screen. The vBlank signal is what tells the monitor to begin drawing the next frame, representing the end of the current data set and marking the beginning of a new one. By varying the length of time this vBlank signal is set to, you can force the monitor to wait any amount of time necessary, allowing the GPU to end the vBlank instance exactly when a new frame is done drawing. The result is a variable refresh rate monitor, one that is in tune with the GPU render rate, rather than opposed to it. Why is that important? I wrote in great detail about this previously, and it still applies in this case:
The idea of G-Sync (and FreeSync) is pretty easy to understand, though the implementation method can get a bit more hairy. G-Sync (and FreeSync) introduces a variable refresh rate to a monitor, allowing the display to refresh at wide range of rates rather than at fixed intervals. More importantly, rather than the monitor dictating what rate this refresh occurs at to the PC, the graphics now tells the monitor when to refresh in a properly configured G-Sync (and FreeSync) setup. This allows a monitor to match the refresh rate of the screen to the draw rate of the game being played (frames per second) and that simple change drastically improves the gaming experience for several reasons.
Gamers today are likely to be very familiar with V-Sync, short for vertical sync, which is an option in your graphics card’s control panel and in your game options menu. When enabled, it forces the monitor to draw a new image on the screen at a fixed interval. In theory, this would work well and the image is presented to the gamer without artifacts. The problem is that games that are played and rendered in real time rarely fall into a very specific frame rate. With only a couple of exceptions, games frame rates will fluctuate based on the activity happening on the screen: a rush of enemies, a changed camera angle, an explosion or falling building. Instantaneous frame rates can vary drastically, from 30, to 60, to 90, and force the image to be displayed only at set fractions of the monitor's refresh rate, which causes problems.
It has been an abnormal week for us here at PC Perspective. Our typical review schedule has pretty much flown out the window, and the past seven days have been filled with learning, researching, retesting, and publishing. That might sound like the norm, but in these cases the process was initiated by tips from our readers. Last Saturday (24 Jan), a few things were brewing:
- Ryan was informed by NVIDIA that the memory layout of the GTX 970 was different than expected.
- The huge (now 168 page) overclock.net forum thread about the Samsung 840 EVO slowdown was once again gaining traction.
- Someone got G-Sync working on a laptop integrated display.
We had to do a bit of triage here of course, as we can only research and write so quickly. Ryan worked the GTX 970 piece as it was the hottest item. I began a few days of research and testing on the 840 EVO slow down issue reappearing on some drives, and we kept tabs on that third thing, which at the time seemed really farfetched. With those two first items taken care of, Ryan shifted his efforts to GTX 970 SLI testing while I shifted my focus to finding out of there was any credence to this G-Sync laptop thing.
A few weeks ago, an ASUS Nordic Support rep inadvertently leaked an interim build of the NVIDIA driver. This was a mobile driver build (version 346.87) focused at their G751 line of laptops. One recipient of this driver link posted it to the ROG forum back on the 20th. A fellow by the name Gamenab, owning the same laptop cited in that thread, presumably stumbled across this driver, tried it out, and was more than likely greeted by this popup after the installation completed:
Now I know what you’re thinking, and it’s probably the same thing anyone would think. How on earth is this possible? To cut a long story short, while the link to the 346.87 driver was removed shortly after being posted to that forum, we managed to get our hands on a copy of it, installed it on the ASUS G751 that we had in for review, and wouldn’t you know it we were greeted by the same popup!
Ok, so it’s a popup, could it be a bug? We checked NVIDIA control panel and the options were consistent with that of a G-Sync connected system. We fired up the pendulum demo and watched the screen carefully, passing the machine around the office to be inspected by all. We then fired up some graphics benchmarks that were well suited to show off the technology (Unigine Heaven, Metro: Last Light, etc), and everything looked great – smooth steady pans with no juddering or tearing to be seen. Ken Addison, our Video Editor and jack of all trades, researched the panel type and found that it was likely capable of 100 Hz refresh. We quickly dug created a custom profile, hit apply, and our 75 Hz G-Sync laptop was instantly transformed into a 100 Hz G-Sync laptop!
Ryan's Note: I think it is important here to point out that we didn't just look at demos and benchmarks for this evaluation but actually looked at real-world gameplay situations. Playing through Metro: Last Light showed very smooth pans and rotation, Assassin's Creed played smoothly as well and flying through Unigine Heaven manually was a great experience. Crysis 3, Battlefield 4, etc. This was NOT just a couple of demos that we ran through - the variable refresh portion of this mobile G-Sync enabled panel was working and working very well.
At this point in our tinkering, we had no idea how or why this was working, but there was no doubt that we were getting a similar experience as we have seen with G-Sync panels. As I digested what was going on, I thought surely this can’t be as good as it seems to be… Let’s find out, shall we?
NVIDIA's G-Sync technology and the monitors that integrate it continue to be one of hottest discussion topics surrounding PC technology and PC gaming. We at PC Perspective have dived into the world of variable refresh rate displays in great detail, discussing the technological reasons for it's existence, talking with co-creator Tom Petersen in studio, doing the first triple-panel Surround G-Sync testing as well as reviewing several different G-Sync monitor's available on the market. We were even the first to find the reason behind the reported flickering a 0 FPS on G-Sync monitors.
A lot of has happened in the world of displays in the year or more since NVIDIA first announced G-Sync technology including a proliferation of low cost 4K panels as well as discussion of FreeSync, AMD's standards-based alternative to G-Sync. We are still waiting for our first hands on time (other than a static demo) with monitors supporting FreeSync / AdaptiveSync and it is quite likely that will occur at CES this January. If it doesn't, AMD is going to have some serious explaining to do...
But today we are looking at the new Acer XB270H, a 1920x1080 27-in monitor with G-Sync support and a 144 Hz refresh rate; a unique combination. In fact, there is no other 27-in 144 Hz 1080p monitor on the market that we are aware of after a quick search of Newegg.com and Amazon.com. But does this monitor offer the same kind of experience as the ASUS ROG Swift PG278Q or even the Acer XB280HK 4K G-Sync panels?
We’ve been tracking NVIDIA’s G-Sync for quite a while now. The comments section on Ryan’s initial article erupted with questions, and many of those were answered in a follow-on interview with NVIDIA’s Tom Petersen. The idea was radical – do away with the traditional fixed refresh rate and only send a new frame to the display when it has just completed rendering by the GPU. There are many benefits here, but the short version is that you get the low-latency benefit of V-SYNC OFF gaming combined with the image quality (lack of tearing) that you would see if V-SYNC was ON. Despite the many benefits, there are some potential disadvantages that come from attempting to drive an LCD panel at varying periods of time, as opposed to the fixed intervals that have been the norm for over a decade.
As the first round of samples came to us for review, the current leader appeared to be the ASUS ROG Swift. A G-Sync 144 Hz display at 1440P was sure to appeal to gamers who wanted faster response than the 4K 60 Hz G-Sync alternative was capable of. Due to what seemed to be large consumer demand, it has taken some time to get these panels into the hands of consumers. As our Storage Editor, I decided it was time to upgrade my home system, placed a pre-order, and waited with anticipation of finally being able to shift from my trusty Dell 3007WFP-HC to a large panel that can handle >2x the FPS.
Fast forward to last week. My pair of ROG Swifts arrived, and some other folks I knew had also received theirs. Before I could set mine up and get some quality gaming time in, my bro FifthDread and his wife both noted a very obvious flicker on their Swifts within the first few minutes of hooking them up. They reported the flicker during game loading screens and mid-game during background content loading occurring in some RTS titles. Prior to hearing from them, the most I had seen were some conflicting and contradictory reports on various forums (not limed to the Swift, though that is the earliest panel and would therefore see the majority of early reports), but now we had something more solid to go on. That night I fired up my own Swift and immediately got to doing what I do best – trying to break things. We have reproduced the issue and intend to demonstrate it in a measurable way, mostly to put some actual data out there to go along with those trying to describe something that is borderline perceptible for mere fractions of a second.
First a bit of misnomer correction / foundation laying:
- The ‘Screen refresh rate’ option you see in Windows Display Properties is actually a carryover from the CRT days. In terms of an LCD, it is the maximum rate at which a frame is output to the display. It is not representative of the frequency at which the LCD panel itself is refreshed by the display logic.
- LCD panel pixels are periodically updated by a scan, typically from top to bottom. Newer / higher quality panels repeat this process at a rate higher than 60 Hz in order to reduce the ‘rolling shutter’ effect seen when panning scenes or windows across the screen.
- In order to engineer faster responding pixels, manufacturers must deal with the side effect of faster pixel decay between refreshes. This is a balanced by increasing the frequency of scanning out to the panel.
- The effect we are going to cover here has nothing to do with motion blur, LightBoost, backlight PWM, LightBoost combined with G-Sync (not currently a thing, even though Blur Busters has theorized on how it could work, their method would not work with how G-Sync is actually implemented today).
With all of that out of the way, let’s tackle what folks out there may be seeing on their own variable refresh rate displays. Based on our testing so far, the flicker only presented at times when a game enters a 'stalled' state. These are periods where you would see a split-second freeze in the action, like during a background level load during game play in some titles. It also appears during some game level load screens, but as those are normally static scenes, they would have gone unnoticed on fixed refresh rate panels. Since we were absolutely able to see that something was happening, we wanted to be able to catch it in the act and measure it, so we rooted around the lab and put together some gear to do so. It’s not a perfect solution by any means, but we only needed to observe differences between the smooth gaming and the ‘stalled state’ where the flicker was readily observable. Once the solder dust settled, we fired up a game that we knew could instantaneously swing from a high FPS (144) to a stalled state (0 FPS) and back again. As it turns out, EVE Online does this exact thing while taking an in-game screen shot, so we used that for our initial testing. Here’s what the brightness of a small segment of the ROG Swift does during this very event:
Measured panel section brightness over time during a 'stall' event. Click to enlarge.
The relatively small ripple to the left and right of center demonstrate the panel output at just under 144 FPS. Panel redraw is in sync with the frames coming from the GPU at this rate. The center section, however, represents what takes place when the input from the GPU suddenly drops to zero. In the above case, the game briefly stalled, then resumed a few frames at 144, then stalled again for a much longer period of time. Completely stopping the panel refresh would result in all TN pixels bleeding towards white, so G-Sync has a built-in failsafe to prevent this by forcing a redraw every ~33 msec. What you are seeing are the pixels intermittently bleeding towards white and periodically being pulled back down to the appropriate brightness by a scan. The low latency panel used in the ROG Swift does this all of the time, but it is less noticeable at 144, as you can see on the left and right edges of the graph. An additional thing that’s happening here is an apparent rise in average brightness during the event. We are still researching the cause of this on our end, but this brightness increase certainly helps to draw attention to the flicker event, making it even more perceptible to those who might have not otherwise noticed it.
Some of you might be wondering why this same effect is not seen when a game drops to 30 FPS (or even lower) during the course of normal game play. While the original G-Sync upgrade kit implementation simply waited until 33 msec had passed until forcing an additional redraw, this introduced judder from 25-30 FPS. Based on our observations and testing, it appears that NVIDIA has corrected this in the retail G-Sync panels with an algorithm that intelligently re-scans at even multiples of the input frame rate in order to keep the redraw rate relatively high, and therefore keeping flicker imperceptible – even at very low continuous frame rates.
A few final points before we go:
- This is not limited to the ROG Swift. All variable refresh panels we have tested (including 4K) see this effect to a more or less degree than reported here. Again, this only occurs when games instantaneously drop to 0 FPS, and not when those games dip into low frame rates in a continuous fashion.
- The effect is less perceptible (both visually and with recorded data) at lower maximum refresh rate settings.
- The effect is not present at fixed refresh rates (G-Sync disabled or with non G-Sync panels).
This post was primarily meant as a status update and to serve as something for G-Sync users to point to when attempting to explain the flicker they are perceiving. We will continue researching, collecting data, and coordinating with NVIDIA on this issue, and will report back once we have more to discuss.
During the research and drafting of this piece, we reached out to and worked with NVIDIA to discuss this issue. Here is their statement:
"All LCD pixel values relax after refreshing. As a result, the brightness value that is set during the LCD’s scanline update slowly relaxes until the next refresh.
This means all LCDs have some slight variation in brightness. In this case, lower frequency refreshes will appear slightly brighter than high frequency refreshes by 1 – 2%.
When games are running normally (i.e., not waiting at a load screen, nor a screen capture) - users will never see this slight variation in brightness value. In the rare cases where frame rates can plummet to very low levels, there is a very slight brightness variation (barely perceptible to the human eye), which disappears when normal operation resumes."
So there you have it. It's basically down to the physics of how an LCD panel works at varying refresh rates. While I agree that it is a rare occurrence, there are some games that present this scenario more frequently (and noticeably) than others. If you've noticed this effect in some games more than others, let us know in the comments section below.
(Editor's Note: We are continuing to work with NVIDIA on this issue and hope to find a way to alleviate the flickering with either a hardware or software change in the future.)
Since the introduction of the first low cost 4K TVs in the form of the SEIKI SE50UY04, and then into the wild world of MST 4K monitors from ASUS and others, and finally with the release of single stream low cost 4K panels, PC Perspective has been covering the monitor resolution revolution heavily. Just look at these reviews:
- SEIKI SE50UY04 50-in 4K 3840x2160 TV Unboxing and Preview
- SEIKI SE39UY04 39-in 4K 3840x2160 TV Unboxing and Overview
- ASUS PQ321Q 31.5-in 4K 60 Hz Tiled Monitor Review
- Samsung U28D590D 28-in 4K Single Stream 60 Hz Monitor
- ASUS PB287Q 4K UHD 28-in Monitor Review
- Acer XB280HK 28-in 4K G-Sync Monitor Review
Today we bring in another vendor's 4K consumer monitor and put it to the test, pitting against the formidable options from ASUS, Samsung, Acer and others. The Philips 288P6LJEB 4K 60 Hz monitor closely mirrors many of the specifications and qualities of other low-cost 4K panels, but with a couple of twits that help it stand out.
The Philips display is a 28-in class TN panel, has a 60 Hz refresh rate when utilizing the DisplayPort 1.2 connection option but adds connection capability that most other 4K panels in this price range leave off. Here are the specs from Philips: