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.)
Subject: Graphics Cards | November 29, 2014 - 09:57 AM | Sebastian Peak
Tagged: pcie, PCI Express, nvidia, mini-itx, GTX 970, graphics card, geforce, directcu mini, DirectCU, asus
ASUS has announced a tiny new addition to their GTX 970 family, and it will be their most powerful mini-ITX friendly card yet with a full GeForce GTX 970 GPU.
Image credit: ASUS
The ASUS 970 DirectCU Mini card will feature a modest factory overclock on the GTX 970 core running at 1088 MHz (stock 1050 MHz) with a 1228 MHz Boost Clock (stock 1178 MHz). Memory is not overclocked and remains at the stock 7 GHz speed.
The GTX 970 DirectCU Mini features a full backplate. Image credit: ASUS
The ASUS GTX 970 DirectCU Mini uses a single 8-pin PCIe power connector in place of the standard dual 6-pin configuration, which shouldn’t be a problem considering the 150W spec of the larger connector (and 145W NVIDIA spec of the 970).
Part of this complete mITX gaming breakfast. Image credit: ASUS
The tiny card offers a full array of display outputs including a pair of dual-link DVI connectors, HDMI 2.0, and DisplayPort 1.2. No word yet on pricing or availability, but the product page is up on the ASUS site.
Subject: Systems | November 25, 2014 - 03:48 PM | Jeremy Hellstrom
Tagged: asus, STRIX GTX 980, i5-4670K, scythe, Kotetsu, quiet computing, Z97-PRO
Silent PC Review has put together their recommendations on how you can build a powerful computer which runs very quietly. The recommended component list certainly lives up to a high powered gaming machine, a STRIX GTX 980, a 3.4GHz i5-4670 and 8GB of DDR3-1866 running on the Asus Z97-PRO. For cooling they chose an air cooler, specifically the Scythe Kotetsu as in their opinion most of the AIO watercoolers have loud fans on their radiators which defeats the purpose of this build. The enclosure of choice is the sound dampened Fractal Design Define R4 with a be quiet! Straight Power 10 600W as opposed to a passively cooled PSU as the excess heat would mean the rest of the fans would need to spin faster to dissipate it. Check out the full article for their alternative suggestions as well as the finished results of the builds.
"The first of our quiet gaming build guides for the season is an ATX tower featuring the highly efficient NVIDIA GeForce GTX 980. Join us as we plan, build, and stress test this beast, while trying to keep it quiet enough to satisfy our own high standards. A sneak preview: We managed to keep it under 20 dBA@1m under all test conditions!"
Here are some more Systems articles from around the web:
- MSI GS30 Shadow and GamingDock Preview @ Kitguru
- ECS LIVA White Edition 64GB Mini PC Kit @ Legion Hardware
- Shuttle Barebone XH81 Review @ Madshrimps
Subject: Motherboards | November 18, 2014 - 01:57 PM | Jeremy Hellstrom
Tagged: asus, Rampage V Extreme, X99, ASUS ROG
The Rampage V Extreme is the new high end X99 board in ASUS' Republic of Gamers series and carries a very high price. The list of extras that are included are impressive, ranging from T-Topology to minimize electrical crosstalk to an ASUS OC socket and LN2 mode as well as physical extras such as the ROG OC panel which allows you to adjust voltages and frequencies via manual controls as well as adjusting fan speeds and other system variables. The output options are very impressive, a dozen SATA ports and two SATA Express ports, ten USB 3.0 ports, 3 WiFi antenna connections as well as optical audio output and gold plated mini-stereo jacks for use with the SupremeFX 8 channel audio codec. [H]ard|OCP takes you on a tour of this incredible board, the overclocking software and more in their latest motherboard review.
"The Rampage V Extreme needs no introduction. It is the flagship of the ASUS Republic of Gamers aka ROG product line. If the pattern of previous Rampage motherboards holds it should be one of the best motherboards money can buy. Is the new ROG crown jewel still worthy of the crown at its $475 price point?"
Here are some more Motherboard articles from around the web:
- ASUS X99-A @ Benchmark Reviews
- ASRock X99 Extreme11 @ Kitguru
- Gigabyte X99-UD4 @ Kitguru
- ASUS Maximus VII Hero mainboard @ HardwareOverclock
- Biostar Hi-Fi Z97Z7 Motherboard Review @ Modders-Inc
- ASUS Z97-PRO LGA1150 @ Silent PC Review
- MSI Z97 Gaming 9 AC Motherboard Review @ Techgage
- ASUS Crossblade Ranger (FM2+) @ eTeknix
Subject: General Tech | November 14, 2014 - 01:27 PM | Jeremy Hellstrom
Tagged: asus, gigabyte, sales, motherboards
If you prefer to talk about the sheer number of sales then ASUS is on track to take top spot with roughly 22 million units sold over 2014, a jump of over just 1 million from last year and 2 more than Gigabyte's predicted sales of 20 million units. ASUS will also hold on to the most profit this year, Gigabyte is expected to match last year's profit of about 97 million USD which falls short of ASUS' expected 130 million USD but that is not the whole story. Last year ASUS closed out with over 160 million USD profit which shows a significant decline in their profitability during the same period that Gigabyte's profitability remained the same. DigiTimes reports this as being due to increased spending by ASUS on marketing and price cuts on their motherboards. Is it possible that ASUS' once insurmountable lead in the motherboard market could be a thing of the past?
"Asustek Computer's motherboard shipments returned to six million units in the third quarter thanks to its aggressive price-cutting strategy, which helped the vendor slightly widen the gap with its major competitors Gigabyte Technology, according to sources from the motherboard industry. However, despite the fact that Asustek is estimated to ship more motherboards than Gigabyte in 2014, its profit growth may perform weaker than Gigabyte's."
Here is some more Tech News from around the web:
- Heartbleed and Windows bugs don't make for an insecure cloud @ The Inquirer
- Graphics Card Coil Whine; An Investigation @ Hardware Canucks
- Pay-by-bonk chip lets hackers pop all your favourite phones @ The Register
- The TR Podcast 165: Game reqs get inflated, benchmarks get weird, and Asus nails the X99-A
Subject: Graphics Cards | November 10, 2014 - 03:45 PM | Jeremy Hellstrom
Tagged: asus, strix, GTX 970 STRIX DirectCU II OC, GTX 970, nvidia, maxwell
When ASUS originally kicked off their new STRIX line they gained popularity not only due to the decent overclock and efficient custom cooler but also because there was only a small price premium over the base model. At a price of $400 on Amazon the card has a price inline with other overclocked models, some base models can be up to $50 less. [H]ard|OCP investigated this card to see what benefits you could expect from the model in this review, comparing it to the R290 and 290X. Out of the box the card runs at a core of 1253 -1266MHz and memory of 7GHz, with a bit of overvolting they saw a stable core of 1473 - 1492MHz and memory of 7.832GHz.
With the new price of the 290X dipping as low as $330 it makes for an interesting choice for GPU shoppers. The NVIDIA card is far more power efficient and the fans operate at 0dB until the GPU hits 65C, which [H] did not see until after running at full load for a time and even then the highest their manually overclocked card hit was 70C. On the other hand the AMD card costs $70 less and offers very similar performance. It is always nice to see competition in the market.
"Today we examine ASUS' take on the GeForce GTX 970 video card. We have the ASUS GTX 970 STRIX DirectCU II OC video card today, and will break down its next-gen performance against an AMD Radeon R9 290 and R9 290X. This video card features 0dB fans, and many factors that improve its chance of extreme overclocking."
Here are some more Graphics Card articles from around the web:
- Alien: Isolation - Video Card Performance @ [H]ard|OCP
- GTX 970 Roundup (EVGA, GALAX, Gigabyte) @ Hardware Canucks
- MSI GTX 980 Gaming 4G Review @ OCC
- Nvidia GeForce GTX 980 @ X-bit Labs
- MSI GeForce GTX 970 Gaming 4G @ X-bit Labs
- Gainward GTX 980 & GTX 970 Phantom @ Legion Hardware
- NZXT Kraken G10 Graphics Adapter: Cooler, and also Quieter @ Silent PC Reivew
- AMD's Windows Catalyst Driver Remains Largely Faster Than Linux Drivers @ Phoronix
- HIS R9 285 IceQ X2 OC 2GB GDDR5 Video Card Review @ Madshrimps
- Sapphire R9 290X Vapor X 8GB CF @ Kitguru
- Sapphire Radeon R9 290X Vapor-X OC 8GB @ eTeknix
Subject: Motherboards | November 6, 2014 - 06:18 PM | Jeremy Hellstrom
Tagged: x99-a, X99, Intel, Haswell-E, asus
At $258 the ASUS X99-A is one of the more affordably priced X99 motherboards on the market and The Tech Report thoroughly tested it to see what, if anything, is lacking. The board still has the "OC Socket" with extra pins which allow the certifiably insane to up their CPU voltage to 1.8V, it retains the M.2 socket, the DDR4 can hit 3000MHz even with all 8 slots populated and three of its six PCIe slots can be used together for SLI or Crossfire. In fact The Tech Report has a very nice illustration showing how the board works with both 28 lane and 40 lane Haswell-E processors. Check out the results of their testing right here.
"Rather than loading up on flashy extras and extraneous accessories, Asus' X99-A motherboard focuses on the basics. It has a sensible spec, loads of builder-friendly features, and a diverse array of powerful tweaking options. Read on to see what makes this our favorite Haswell-E motherboard to date."
Here are some more Motherboard articles from around the web:
- ASUS X99-PRO Motherboard @ Hardware Secrets
- Gigabyte Z97N-Gaming 5 @ eTeknix
- Gigabyte X99 SOC Force Overclocking Motherboard Review @ Hardware Asylum
- Asus Maximus VII Gene Motherboard Review @ TechwareLabs
- ASRock QC5000-ITX Motherboard (and A4-5000 CPU) @ Hardware Secrets
Introduction and Technical Specifications
Courtesy of ASUS
The ASUS Maximus VII Formula motherboard is one of the newest members of the ROG (Republic of Gamers) product line, integrating several new features to elevate the board to an entirely new level over is predecessor. From outward appearance the Maximus VII Formula looks very similar to its previous revision, the Maximus VI Formula. However, ASUS made some under-the-hood enhancements and minor layout adjustments to the board, utilizing the functionality of the integrated Intel Z97 chipset. The Maximus VII Formula comes with a premium MSRP of $369.00, but is well worth the cost given the premium feature set and performance potential of the board.
Courtesy of ASUS
Courtesy of ASUS
Courtesy of ASUS
ASUS designed the Maximus VII Formula motherboard with a top-rated 8-phase digital power delivery system, combining 60A-rated BlackWing chokes, NexFET MOSFETs with a 90% efficiency rating, and 10k Japanese-source Black Metallic capacitors, for unprecedented system stability under any circumstance. Additionally, ASUS integrate their updated SupremeFX Formula audio system for superior audio fidelity through the integrated audio ports. The Maximus VII Formula contains the following features integrated into its design: six SATA 3 ports; an M.2 (NGFF) 10 Gb/s port integrated into the ASUS mPCIe Combo III card; two SATA Express 10 Gb/s ports; an Intel I218V GigE NIC; an AzureWave (Broadcomm chipset) 802.11ac Wi-Fi and Bluetooth controller integrated into the ASUS mPCIe Combo III card; three PCI-Express Gen3 x16 slots; three PCI-Express Gen2 x1 slots; 2-digit diagnostic LED display; on-board power, reset, CMOS clear, Keybot, MemOK!, BIOS Flashback, ROG Connect, and Sonic SoundStage buttons; Probelt voltage measurement points; OC Panel support; SupremeFX Formula 2014 audio solution; CrossChill Hybrid air and water cooled VRM copper-based cooling solution; ROG Armor overlay; and USB 2.0 and 3.0 port support.
Subject: Graphics Cards | September 26, 2014 - 02:22 PM | Jeremy Hellstrom
Tagged: asus, ROG, gtx 780 ti, MATRIX Platinum, DirectCU II
With the release of the new Maxwell cards comes an opportunity for those with a smaller budget to still get a decent upgrade for their systems. Early adopters will often sell their previous GPUs once they've upgraded allowing you to get a better card than your budget would usually allow, though with a risk of ending up with a bum card. The ASUS ROG GTX 780 Ti MATRIX Platinum is a good example with a DirectCU II air cooler for general usage but the LN2 switch will also allow more extreme cooling methods for those looking for something a little more impressive. The factory overclock is not bad at 1006/1072MHz core and 7GHz effective memory but the overclock [H]ard|OCP managed at 1155/1220MHz and 7.05GHz pushes the performance above that of the R9 290X of the same family. If you can find this card used at a decent price it could give you more of an upgrade than you thought you could afford.
"In today's evaluation we are breaking down the ASUS ROG GTX 780 Ti MATRIX Platinum video card. We put this head-to-head with the ASUS ROG R9 290X MATRIX Platinum. Which provides a better gaming experience, best overclocking performance, and power and temperature? Which one provides the best value? "
Here are some more Graphics Card articles from around the web:
- MSI GTX 980 OC @ HardwareHeaven
- Taking It To The Limit: Overclocking NVIDIA’s GeForce GTX 970 & 980 @ Techgage
- Gigabyte G1 Gaming Geforce GTX 980 Review @ HiTech Legion
- Palit GTX 970 JetStream 4 GB @ techPowerUp
- ASUS Strix Edition GeForce GTX 970 Graphics Card Review @ Techgage
- ASUS GTX 970 STRIX OC Review @ Hardware Canucks
- Palit GTX970 JetStream OC @ Kitguru
- Testing Nvidia’s GeForce GTX 980 4GB Graphics Cards In SLI @ eTeknix
- Gigabyte G1 Gaming GeForce GTX 980 4GB @ eTeknix
- ASUS STRIX GTX 970 DirectCU II OC 4GB Review @HiTech Legion
- Nvidia GeForce GTX 980 4GB @ eTeknix
- MSI GTX 970 Gaming 4G Review @HiTech Legion
- Nvidia Quadro K5200, K4200 and K2200 Professional Graphics Cards @ X-bit Labs
- Gigabyte R7 250X OC Performance Review @ Neoseeker
- Sapphire R9 285 ITX Compact v MSI GTX760 Gaming Mini ITX @ Kitguru
Subject: General Tech | September 24, 2014 - 12:56 PM | Jeremy Hellstrom
Tagged: amd, nvidia, hp, dell, asus, acer, toshibe, mobile gpu
The growing market of low cost $200 to $400 10" to 15" laptops is expected to cut into the sales of AMD and NVIDIA's mobile GPUs as they are forced to focus more on higher end models. That is a much smaller market and the margins generally favour the laptop vendor as opposed to the company providing the mobile GPU. This will be felt more strongly by NVIDIA as AMD's APU lineup will appear in the smaller and less expensive notebooks but will still have an effect on AMD's bottom line over the coming quarters. DigiTimes also mentioned that AMD's R9 390X is due out in the first half of 2015 and that both companies are currently reducing the price of their GPUs in the hopes of increasing their sales volumes on the desktop.
"Notebook vendors including Hewlett-Packard (HP), Dell, Lenovo, Asustek Computer, Acer and Toshiba, will launch low-cost models with CPUs with integrated graphics in the fourth quarter of 2014 and therefore AMD and Nvidia are expected to see demand for their discrete mobile GPUs decrease, according to Taiwan-based supply chain makers."
Here is some more Tech News from around the web:
- The TR Podcast 162: Apple's biggest and Nvidia's fastest
- Adobe swallows Aviary, hopes to stuff Creative Cloud into mobes @ The Register
- Blackberry Passport arrives, claims to outperform the iPhone 6 and Galaxy S5 @ The Inquirer
- ARM gives Internet of Things a PIECE of its MIND – the Cortex-M7 @ The Register
- Why the Convergent Desktop is So Important to Linux @ Linux.com
- Le whoops! Microsoft France boss blows lid off 'Windows 9' event @ The Register
- Microsoft to cut Windows 7 OEM supply on 31 October @ The Inquirer