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: General Tech, Graphics Cards | December 2, 2014 - 03:11 AM | Scott Michaud
Tagged: amd, GCN, dice, frostbite
Inverse trigonometric functions are difficult to compute. Their use is often avoided like the plague. If, however, the value is absolutely necessary, it will probably be solved by approximations or, if possible, replacing them with easier functions by clever use of trig identities.
If you want to see how the experts approach this problem, then Sébastien Lagarde, a senior developer of the Frostbite engine at DICE, goes into detail with a blog post. By detail, I mean you will see some GPU assembly being stepped through by the end of it. What makes this particularly interesting is the diagrams at the end, showing what each method outputs as represented by the shading of a sphere.
If you are feeling brave, take a look.
Subject: Graphics Cards | December 1, 2014 - 02:52 PM | Jeremy Hellstrom
Tagged: msi, nvidia, GTX 980, GAMING 4G, factory overclocked, Twin Frozr V
MSI has updated their Twin Frozr V with Torx fans which are effective at moving a lot of air very quietly and 'S' shaped heatpipes which bear the name SuperSU. Connectivity is provided by dual-link DVI-I, HDMI and three DisplayPort plugs which ought to provide enough flexibility for anyone. It is clocked at 1216 - 1331MHz out of the box with GDDR5 running at 7GHz effective which [H]ard|OCP managed to increase to 1406 - 1533MHz and 7.16GHz on the memory which is rather impressive for a Maxwell chip with NVIDIA's power limits and shows just how much you can squeeze out of their new chip without needing to up the amount of juice you are providing it. The overclocked card upped the full system wattage to 378W which was much lower than the R9 290 they tested against and the GPU temperature went as high as 70C when pushed to the limit which again is lower than the 290 however NVIDIA's selling price is certainly higher than AMD's. Check out their full review here.
"The MSI GTX 980 GAMING 4G video card has a factory overclock and the new Twin Frozr V cooling system. We'll push it to its highest custom overclock and pit it against the ASUS ROG R9 290X MATRIX Platinum overclocker, and determine the gaming bang for your buck. May the best card win."
Here are some more Graphics Card articles from around the web:
- NVIDIA Multi-Frame Sampled AA @ [H]ard|OCP
- OcUK GeForce GTX 970 'NVIDIA 970 Cooler Edition' @ Kitguru
- EVGA GTX 980 Classified Video Card Review @ Hardware Asylum
- EVGA GeForce GTX 970 FTW ACX 2.0 Review @ Hardware Canucks
- MSI GTX 980 Gaming 4G Review @ Neoseeker
It has been a couple of months since the release of the GeForce GTX 970 and the GM204 GPU that it is based on. After the initial wave of stock on day one, NVIDIA had admittedly struggled to keep these products available. Couple that with rampant concerns over coil whine from some non-reference designs, and you could see why we were a bit hesitant to focus and spend our time on retail GTX 970 reviews.
These issues appear to be settled for the most part. Finding GeForce GTX 970 cards is no longer a problem and users with coil whine are getting RMA replacements from NVIDIA's partners. Because of that, we feel much more comfortable reporting our results with the various retail cards that we have in house, and you'll see quite a few reviews coming from PC Perspective in the coming weeks.
But let's start with the MSI GeForce GTX 970 4GB Gaming card. Based on user reviews, this is one of the most popular retail cards. MSI's Gaming series of cards combines a custom cooler that typically runs quieter and more efficient than reference design, and it comes with a price tag that is within arms reach of the lower cost options as well.
The MSI GeForce GTX 970 4GB Gaming
MSI continues with its Dragon Army branding, and its associated black/red color scheme, which I think is appealing to a wide range of users. I'm sure NVIDIA would like to see a green or neutral color scheme, but hey, there are only so many colors to go around.
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: Graphics Cards | November 20, 2014 - 07:08 PM | Jeremy Hellstrom
Tagged: sli, NVIDA, GTX 970
The contestants are lined up in [H]ard|OCP's test bench, at around $700 you have a pair of GTX 970's and in the same weight class are a pair of R9 290X cards, next weighing in at just under $550 are two R9 290s, and rounding out the completion are a pair of GTX 780's who punch somewhere between $800 to $1000 depending on when you look. The cards are tested for their ability to perform on a 4K stage as well as in the larger 5760x1200 multi-monitor event. After a long and gruelling battle the extra work the 290X put into trimming its self down and fitting into a lower weight class has proven to be well worth the effort as they managed to show up the 970's in every performance category although certainly not in power efficiency. Any of these pairings will be powerful but none can match a pair of GTX 980's who are also in a price class all by themselves.
"We take 2-Way NVIDIA GeForce GTX 970 SLI for a spin and compare it to R9 290X CF, R9 290 CF, GTX 780 SLI at 4K resolution as well as NV Surround on a triple-display setup. If you want to see how all these video cards compare in these different display configurations we've got just the thing. Find out what $700 SLI gets you."
Here are some more Graphics Card articles from around the web:
- ZOTAC GeForce GTX 970 AMP! Extreme Edition @ Bjorn3d
- MSI GTX 970 Gaming 4G Review @ OCC
- Gigabyte GTX 970 WindForce 3X @ HardwareOverclock
- NVIDIA GeForce GTX 980 SLI Overclocked @ [H]ard|OCP
- MSI GTX 980 Gaming 4G @ Bjorn3D
- Raijintek Morpheus VGA Cooler Review @ Hardware Asylum
- AMD Radeon Gallium3D Is Catching Up & Sometimes Beating Catalyst On Linux @ Phoronix
MFAA Technology Recap
In mid-September NVIDIA took the wraps off of the GeForce GTX 980 and GTX 970 GPUs, the first products based on the GM204 GPU utilizing the Maxwell architecture. Our review of the chip, those products and the package that NVIDIA had put together was incredibly glowing. Not only was performance impressive but they were able to offer that performance with power efficiency besting anything else on the market.
Of course, along with the new GPU were a set of new product features coming along for the ride. Two of the most impressive were Dynamic Super Resolution (DSR) and Multi-Frame Sampled AA (MFAA) but only one was available at launch: DSR. With it, you could take advantage of the extreme power of the GTX 980/970 with older games, render in a higher resolution than your panel, and have it filtered down to match your screen in post. The results were great. But NVIDIA spent as much time talking about MFAA (not mother-fu**ing AA as it turned out) during the product briefings and I was shocked when I found out the feature wouldn't be ready to test or included along with launch.
That changes today with the release of NVIDIA's 344.75 driver, the first to implement support for the new and potentially important anti-aliasing method.
Before we dive into the results of our testing, both in performance and image quality, let's get a quick recap on what exactly MFAA is and how it works.
Here is what I wrote back in September in our initial review:
While most of the deep, architectural changes in GM204 are based around power and area efficiency, there are still some interesting feature additions NVIDIA has made to these cards that depend on some specific hardware implementations. First up is a new antialiasing method called MFAA, or Multi-Frame Sampled AA. This new method alternates the AA sample pattern, which is now programmable via software, in both temporal and spatial directions.
The goal is to change the AA sample pattern in a way to produce near 4xMSAA quality at the effective cost of 2x MSAA (in terms of performance). NVIDIA showed a couple of demos of this in action during the press meetings but the only gameplay we saw was in a static scene. I do have some questions about how this temporal addition is affected by fast motion on the screen, though NVIDIA asserts that MFAA will very rarely ever fall below the image quality of standard 2x MSAA.
That information is still correct but we do have a little bit more detail on how this works than we did before. For reasons pertaining to patents NVIDIA seems a bit less interested in sharing exact details than I would like to see, but we'll work with what we have.
Subject: Graphics Cards | November 14, 2014 - 11:46 AM | Ryan Shrout
Tagged: sli, nvidia, N980X3WA-4GD, maxwell, GTX 980, gigabyte, geforce, 3-way
Earlier this week, a new product showed up on Gigabyte's website that has garnered quite a bit of attention. The GA-N980X3WA-4GD WaterForce Tri-SLI is a 3-Way SLI system with integrated water cooling powered by a set of three GeForce GTX 980 GPUs.
That. Looks. Amazing.
What you are looking at is a 3-Way closed loop water cooling system with an external enclosure to hold the radiators while providing a display full of information including temperatures, fans speeds and more. Specifications on the Gigabyte site are limited for now, but we can infer a lot from them:
- WATERFORCE :3-WAY SLI Water Cooling System
- Real-Time Display and Control
- Flex Display Technology
- Powered by NVIDIA GeForce GTX 980 GPU
- Integrated with 4GB GDDR5 memory 256-bit memory interface(Single Card)
- Features Dual-link DVI-I / DVI-D / HDMI / DisplayPort*3(Single Card)
- BASE: 1228 MHz / BOOST: 1329 MHz
- System power supply requirement: 1200W(with six 8-pin external power connectors)
The GPUs on each card are your standard GeForce GTX 980 with 4GB of memory (we reviewed it here) though they are running at overclocked base and boost clock speeds, as you would hope with all that water cooling power behind it. You will need a 1200+ watt power supply for this setup, which makes sense considering the GPU horsepower you'll have access to.
Another interesting feature Gigabyte is listing is called GPU Gauntlet Sorting.
With GPU Gauntlet™ Sorting, the Gigabyte SOC graphics card guarantees the higher overclocking capability in terms of excellent power switching.
Essentially, Gigabyte is going to make sure that the GPUs on the WaterForce Tri-SLI are the best they can get their hands on, with the best chance for overclocking higher than stock.
Setup looks interesting - the radiators and fans will be in the external enclosure with tubing passing into the system through a 5.25-in bay. It will need to have quick connect/disconnect points at either the GPU or radiator to make that installation method possible.
Pricing and availability are still unknown, but don't expect to get it cheap. With the GTX 980 still selling for at least $550, you should expect something in the $2000 range or above with all the custom hardware and fittings involved.
Can I get two please?
Subject: Graphics Cards | November 13, 2014 - 12:46 PM | Scott Michaud
Tagged: nvidia, geforce, gtx 960, maxwell
It is possible that a shipping invoice fragment was leaked for the NVIDIA GeForce GTX 960. Of course, an image of text on a plain, white background is one of the easiest things to fake and/or manipulate, so take it with a grain of salt.
The GTX 960 is said to have 4GB of RAM on the same, 256-bit bus. Its video outputs are listed as two DVI, one HDMI, and one DisplayPort, making this graphics card useful for just one G-Sync monitor per card. If I'm reading it correctly, it also seems to have a 993 MHz base clock (boost clock unlisted) and an effective 6008 MHz (1500 MHz actual) RAM clock. This is slightly below the 7 GHz (1750 MHz actual) of the GTX 970 and GTX 980 parts, but it should also be significantly cheaper.
The GeForce GTX 960 is expected to retail in the low-$200 price point... some day.
Subject: Graphics Cards | November 12, 2014 - 09:03 PM | Ryan Shrout
Tagged: Unity, ubisoft, assassin's creed
Over the last couple of days there have been a lot of discussions about the performance of the new Assassin's Creed Unity from Ubisoft on current generation PC hardware. Some readers have expressed annoyance that the game is running poorly, at lower than expected frame rates, at a wide range of image quality settings. Though I haven't published my results yet, we are working on a story comparing NVIDIA and AMD GPUs in Unity, but the truth is that this is occurring on GPUs from both sides.
For example, using a Core i7-3960X and a single GeForce GTX 980 4GB reference card, I see anywhere from 37 FPS to 48 FPS while navigating the crowded city of Paris at 1920x1080 and on the Ultra High preset. Using the Low preset, that frame rate increases to 65-85 FPS or so.
Clearly, those are lower frame rates at 1920x1080 than you'll find in basically any other PC game on the market. The accusation from some in the community is that Ubisoft is either doing this on purpose or doing it out of neglect with efficient code. I put some questions to the development team at Ubisoft and though I only had a short time with them, the answers tell their side of the story.
Ryan Shrout: What in the Unity game engine is putting the most demand on the GPU and its compute resources? Are there specific effects or were there specific design goals for the artists that require as much GPU horsepower as the game does today with high image quality settings?
Ubisoft: Assassin’s Creed Unity is one of the most detailed games on the market and [contains] a giant, open world city built to the scale that we’ve recreated. Paris requires significant details. Some points to note about Paris in Assassin’s Creed Unity:
- There are tens of thousands of objects are visible on-screen, casting and receiving shadows.
- Paris is incredibly detailed. For example, Notre-Dame itself is millions of triangles.
- The entire game world has global illumination and local reflections.
- There is realistic, high-dynamic range lighting.
- We temporally stabilized anti-aliasing.
RS: Was there any debate internally about downscaling on effects/image quality to allow for lower end system requirements?
Ubisoft: We talked about this a lot, but our position always came back to us ensuring that Assassin’s Creed Unity is a next-gen only game with breakthrough graphics. With this vision, we did not degrade the visual quality of the game. On PC, we have several option for low-scaling, like disabling AA, decreasing resolution, and we have low option for Texture Quality, Environment Quality and Shadows.
RS: Were you looking forward or planning for future GPUs (or multi-GPU) that will run the game at peak IQ settings at higher frame rates than we have today?
Ubisoft: We targeted existing PC hardware.
RS: Do you envision updates to the game or to future GPU drivers that would noticeably improve performance on current generations of hardware?
Ubisoft: The development team is continuing to work on optimization post-launch through software updates. You’ll hear more details shortly.
Some of the features listed by the developer in the first answer - global illumination methods, high triangle counts, HDR lighting - can be pretty taxing on GPU hardware. I know there are people out there pointing out games that have similar feature sets and that run at higher frame rates, but the truth is that no two game engines are truly equal. If you have seen Assassin's Creed Unity in action you'll be able to tell immediately the game is beautiful, stunningly so. Is it worth that level of detail for the performance levels achieved from current high-end hardware? Clearly that's the debate.
When I asked if Ubisoft had considered scaling back the game to improve performance, they clearly decided against it. The developer had a vision for the look and style of the game and they were dedicated to it; maybe to a fault from some gamers' viewpoint.
Also worth nothing is that Ubisoft is continuing to work on optimization post-release; how much of an increase we'll actually see with game patches or driver updates will have to be seen as we move forward. Some developers have a habit of releasing a game and simply abandoning it as it shipped - hopefully we will see more dedication from the Unity team.
So, if the game runs at low frame rates on modern hardware...what is the complaint exactly? I do believe that Ubisoft would have benefited from better performance on lower image quality settings. You can tell by swapping the settings for yourself in game but the quality difference between Low and Ultra High is noticeable, but not dramatically so. Again, this likely harkens back to the desire of Ubisoft to maintain an artistic vision.
Remember that when Crysis 3 launched early last year, running at 1920x1200 at 50 FPS required a GTX 680, the top GPU at the time; and that was at the High settings. The Very High preset only hit 37 FPS on the same card.
PC gamers seems to be creating a double standard. On one hand, none of us want PC-ports or games that are developed with consoles in mind that don't take advantage of the power of the PC platform. Games in the Call of Duty series are immensely popular but, until the release of Advanced Warfare, would routinely run at 150-200 FPS at 1080p on a modern PC. Crysis 3 and Assassin's Creed Unity are the opposite of that - games that really tax current CPU and GPU hardware, paving a way forward for future GPUs to be developed and NEEDED.
If you're NVIDIA or AMD, you should applaud this kind of work. Now I am more interested than ever in a GTX 980 Ti, or a R9 390X, to see what Unity will play like, or what Far Cry 4 will run at, or if Dragon Age Inquisition looks even better.
Of course, if we can get more performance from a better optimized or tweaked game, we want that too. Developers need to be able cater to as wide of a PC gaming audience as possible, but sometimes creating a game that can scale between running on a GTX 650 Ti and a GTX 980 is a huge pain. And with limited time frames and budgets, don't we want at least some developers to focus on visual quality rather than "dumbing down" the product?
Let me know what you all think - I know this is a hot-button issue!
UPDATE: Many readers in the comments are bringing up the bugs and artifacts within Unity, pointing to YouTube videos and whatnot. Those are totally valid complaints about the game, but don't necessarily reflect on the game's performance - which is what we were trying to target with this story. Having crashes and bugs in the game is disappointing, but again, Ubisoft and Assassin's Creed Unity aren't alone here. Have you seen the bugs in Skyrim or Tomb Raider? Hopefully Ubisoft will be more aggressive in addressing them in the near future.
UPDATE 2: I also wanted to comment that even though I seem to be defending Ubisoft around the performance of Unity, my direct feedback to them was that they should enable modes in the game that allow it to play at higher frame rates and even lower image quality settings, even if they were unable to find ways to "optimize" the game's efficiency. So far the developer seems aware of all the complaints around performance, bugs, physics, etc. and is going to try to address them.
UPDATE 3: In the last day or so, a couple of other media outlets have posted anonymous information that indicates that the draw call count for Assassin's Creed Unity is at fault for the poor performance of the game on PCs. According to this "anonymous" source, while the consoles have low-level API access to hardware to accept and process several times the draw calls, DirectX 11 can only handle "7,000 - 10,000 peak draw calls." Unity apparently is "pushing in excess of 50,000 draw calls per frame" and thus is putting more pressure on the PC that it can handle, even with high end CPU and GPU hardware. The fact that these comments are "anonymous" is pretty frustrating as it means that even if they are accurate, they can't be taken as the truth without confirmation from Ubisoft. If this turns out to be true, then it would be a confirmation that Ubisoft didn't take the time to implement a DX11 port correctly. If it's not true, or only partially to blame, we are left with more meaningless finger-pointing.