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Hmm, so why would anyone buy a Titan X now? For 1 GB extra (slower) RAM? Did they hobble it in any other way?

Edit: According to Anandtech, "NVIDIA has been surprisingly candid in admitting that unless compute customers need the last 1GB of VRAM offered by the Titan, they’re likely going to buy the GTX 1080 Ti instead."

I would suggest changing the article link to Anandtech, as it's really a much more informative and better written article. Jen-Hsun Huang seems to have bottled his cringe-inducing presentation style and fed it to whoever wrote that PR piece on the Nvidia site. http://www.anandtech.com/show/11172/nvidia-unveils-geforce-g...

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I believe gamers who spend that kind of money on a graphics card do it more for cultural than functional reasons. It's like buying a car model upgrade, that has little practical value, aside from showing off that you could afford it.

It's weird, but that's human nature I guess.

Sure, but gamers would buy the Ti because extra speed is more important than a bit of RAM for gaming. Even machine learning people who need lots of RAM will probably not decide to spend $500 on the Titan XP just for 1 GB.

Yes, but it's not really $500 for 1 GB if you're getting the board for free.

https://developer.nvidia.com/academic_gpu_seeding

VR is pushing higher end video cards at the moment. This card should be amazing at driving VR headsets at max settings.

Agreed, VR is the only thing that maxes out my 1080, aside from ultra-eyecandy shaders.

I have a 980 Ti and it can't always get 60fps at 4K. So for me it's not just shelling out for the biggest card, I'm trying to get the best out of my hardware to make for a better experience.

My brother and his friends are PC gamers, and they were anticipating the Pascal 10x series for over a year because of the improved performance.

Most of them upgraded from the two earlier series, because to get 1440p gaming on the new 144Mhz monitors and with high settings on modern games you really need these new cards.

I had similar thoughts to your own re: the hype, until I saw the games. They are amazing - and I find VR boring after 10 minutes.

What games?

Mainly H1Z1, Battlefield and Overwatch but I also saw GTA V, Fallout 4, FIFA, Battlefront and Witcher.

Both the games that are designed for the higher resolution, as well as the games that 'scale up' (can't recall which was which) are amazing. It's a completely different gaming experience and I understand now how people become obsessed with frame rates, specs, cards, the unveils, the news and rumors etc.

I was so close to pulling the trigger myself even though I don't have a PC. I could probably justify the $500 + $500 for card and monitor on an existing PC (or a Mac upgrade clears throat) but not an entirely new machine to play games.

If you haven't seen cutting edge PC gaming go and check it out somewhere or somehow. There was this entire revolution happening that I knew nothing about.

OK. I've got a PC with gtx970 I occasionally use for gaming, mostly Battlefront (at 1080p, haven't tried 4k). It's pretty good, wouldn't say it blows my mind like the HTC Vive demos I've tried though

>It's a completely different gaming experience and I understand now how people become obsessed with frame rates, specs, cards, the unveils, the news and rumors etc.

I also partly think this is cultural, as the original commenter noted.

Last year shortly after Overwatch came out I built a new gaming PC, featuring an i5 6600K, GTX 980Ti, and 27" 1080p 144Hz monitor. My buddies gave me some flack for it because even at the time (~June 2016) these were not the top of the line options. Nevermind the fact that even with all settings on Ultra I was able to consistently get 120-140 FPS, and with settings turned down to their most basic (a common practice among competitive gamers to decrease input latency) I never dropped below 144, even in the middle of the most dense game play.

Granted, I'm playing at 1080p, but I have yet to find a reason to want more than that, and the performance is where I want it to be, so I'm satisfied. Still, since I didn't trade hundreds of extra dollars for an i7 and a GTX 1080 I'm the noob.

Yet to find a reason to want more than 1080p? Come on...

You're part of the fringe, not the other way around.

I'm a potential customer with enough money to buy basically whatever I want, but nothing about a resolution greater than 1080p has been enticing to me so far (and I own a 4K TV that my feelings are generally "meh" about).

I'm satisfied, so really it's not my problem; it's the problem of the hardware manufacturers and game developers to make better products and do a better job of convincing me that a higher resolution is something I need, and so far they haven't.

Have you tried watch 4k content on Netflix? The difference is not subtle. It's not quite the same leap as DVD->Bluray, but it's not that far off. It's not so much more detail as everything seeming more in focus.

I've watched some of Amazon's 4K content and wasn't particularly blown away. In fact, I had to pause the Fire TV a few times just to see whether or not the stream was still in 4K, because if your network traffic slows down it will revert back to 1080. It wasn't noticeable enough for me on a 50" screen at about 8 feet away.

Have you verified that the HDMI port you're using supports 4K/the nessesary HDCP? I stream netflix directly on my smart TV (as well as youtune 4k), and like I said, the difference is immediately obvious. I suspect you're getting 4k downscaled to 1080p.

It's definitely working -- in fact, the FireTV won't even display the "4K Ultra HD" categories unless it's connected correctly to a compatible TV[0]. I notice the difference if I actively try to, I just don't think it's as mind blowing as everyone is claiming it to be. It's certainly not something I couldn't live without.

[0] https://www.amazon.com/gp/help/customer/display.html?nodeId=...

I lowered game settings to reach 100fps on my 100Hz trinitron screen back in -98 too. Like everything it can be cultural, but to suggest it's only that is ridiculous. People still buy expensive functional clothes, bikes, and everything else. Just because you can work out in a tshirt from H&M on a $100 bike doesn't mean there's no practical value to go more expensive.

> Granted, I'm playing at 1080p, but I have yet to find a reason to want more than that, and the performance is where I want it to be, so I'm satisfied. Still, since I didn't trade hundreds of extra dollars for an i7 and a GTX 1080 I'm the noob.

So what you're saying is that you find a value in playing at 144Hz over 60Hz, but object to people finding value in playing at a higher resolution? Someone else might argue that you paying to play at 144Hz is only cultural, while you know it's not.

>object to people finding value in playing at a higher resolution

Except I didn't object to anything. Me calling the wants and needs of the high performance PC culture "cultural" is not me being dismissive of what they happen to enjoy. Buy whatever you want. My whole point was that you can still have a professional quality (as in eSports level) experience with equipment that's not super-ultra-top-of-the-line-fantastic, saving you the super-ultra-top-of-the-line-fantastic premiums.

> My whole point was that you can still have a professional quality (as in eSports level) experience with equipment that's not super-ultra-top-of-the-line-fantastic, saving you the super-ultra-top-of-the-line-fantastic premiums.

I'm not sure I understand. In this area (as opposed to functional clothing etc) it's very easy to measure real differences between a GTX 1070 and a 1080, and seeing pixels on more than 1080p when the screen is 27" and up.

That you can get a rags-to-riches story in eSports learning to play on a 5 year old computer is very true, but it doesn't detract from the fact that it's easier with better hardware.

If you don't feel it's worth it it's not worth it for you, but the difference is very real.

Personally, I play at 3440x1440. I want 0 bottlenecks and more power than I need, so a 1080Ti is perfect for me. Especially as in the UK I can get it for ~£30 more than I paid for the 1080.

I have a 4K screen and a GTX 1080, I struggle to play most high end games at a stable 4K 60fps with it. VR is an other use case where the extra power is probably not wasted. DOOM 2016 maxed out at 4k is a sight to behold.

Can you tell me (honest question) what improves with 4k for games? I mean, for regular stuff you can see more details on the picture, but games usually just render essentially same picture only for larger resolution. And picture with fullhd and modern capabilities is also already pretty smooth, so does 4k bring anything (I guess it can add a bit of smoothness as additional step of AA)? Is it worth the trouble?

At the current price I don't think it's really worth it, no. Really few games manage to take full advantage of 4K (Doom '16, as I mentioned, is one of them). Too many console ports with low texture resolutions and terrible optimizations these days. Older games will of course fare much better but the additional sharpness in the graphics is probably not worth the price of the hardware. For gaming I think 1440p and a high framerate are a better compromise at the moment.

That being said I have some trouble going back to my 1200p screens at work after being used to 4k at home. Surprisingly even for emacs and other work-related things 4K makes a pretty huge difference in my experience. Everything remains razor sharp even with a small font. I can split my screen and display a few full page datasheets and schematics alongside my code. No need to zoom in or anything. No aliasing, no pixels, I find it very relaxing.

How does Doom take advantage of 4k?

High resolution textures and detailed models coupled with good optimization that makes it run like a charm maxed out at 4k.

I don't have very good screenshots available at the moment unfortunately but this should give you an idea of what's possible:

http://images.akamai.steamusercontent.com/ugc/10059888168078...

http://images.akamai.steamusercontent.com/ugc/10059888168007...

Here's Dark Souls III which looks pretty great at 4K but unfortunately doesn't manage to run at a solid 60FPS on my GTX 1080:

http://images.akamai.steamusercontent.com/ugc/84843325410407...

And here's an older game, The Witcher:

http://images.akamai.steamusercontent.com/ugc/84843969116367...

Those hold up pretty well at 4K. In contrast I present to you Wolfenstein: The New Order which often looks very mediocre and yet manages to run worse than DOOM:

http://images.akamai.steamusercontent.com/ugc/10059888168132...

Note the low polygon count on some of the models and the very low resolution of certain textures.

Thanks.

For 3D the biggest improvement is you have more pixels to render objects at long distance, which is huge for games with large camera viewing distance. For example, you can spot enemy much easier in Battlefield.

I see your point. I guess it also requires much larger screen. Because if 1 pixel man will be moving on my 27-inch fullhd screen, even though on 4k display it will be 4 pixels, it still be same physical size and not much easier to notice :)

It will be 4 pixels of different colors though, making it easier to distinguish the shape of the object.

Everything has More Detail, sometimes more than you care about. In some ways this feels like it's Not Important, except you definitely notice it, especially if your game has sliders that determine how far away they start doing detail culling by using lower-resolution models/textures. I can safely turn off anti-aliasing everywhere, which basically seems to balance that there are 4x as many pixels. ;)

World of Warcraft: Everything looks the same, except text is prettier, item textures are more detailed, and spell icons suddenly have noticeable details. ("Hey that's a guy with a shield! I never noticed that!")

Dishonored, or other FPS-es: Far-away details suddenly are not lost in the haze of antialiasing. Wires and greebling on bridges are visible, and Look Good. HUDs and ammo displays seem to universally SUCK -- they are often not scaled in older games.

All the face textures in most older games end up supporting the higher detail textures, but it gets closer to the uncanny valley. (I notice this a lot in bioshock infinite.) I haven't re-played Wolfenstein.

It's much like looking at the same picture or webpage on a retina screen vs a non-retina screen. Text looks better, some other things look much the same. Anything vector-based (HUDs, etc) might look better.

No, currently monitor technology is evolving fast so GPUs at the are struggling to meet the highest interface requirements, notably 3440x1440@144Hz and 4K@60Hz (and don't even think about more frames at 4K).

I have a GTX 1070 mostly for deep learning, but I have to admit that piece of hardware was pleasing the casual gamer in me as well. It's only about 20% behind a GTX 1080 for gaming, a $500 GPU. Twice more than I had ever spent for leisure as a gamer.

Well on my 4K display, I can push most pre-2014 games to 60 fps, but that's it. After that, for most AAA games, I have to resort to 1440p + some AA. And if I was really into gaming I'd have bought an ultrawide 1440p/144Hz monitor, no doubt about it, knowing pretty well I'd need a Titan XP or at least 1080 to see these framerates on newer titles.

It's a space that's moving fast, both on the interface (monitor, VR...) and processing side (Nvidia makes a 20-30% leap each gen, kind of insane compared to Intel CPU gens for instance). We're only beginning to touch low-level APIs once again after a two-decades hiatus on the PC (DirectX being both great to make it easy to create 3D apps but at the cost of much performance/overhead, which DX12 is trying to address).

I'm jaded about CPUs, honestly Ryzen is much welcome economically but nothing to be enthused as a nerd/engineer, however GPUs and display technology is where it's at these days. Can't wait for proper AR too (HoloLens-like technology, still a few gens away from a commercially viable product).

I'm sorry but while I agree GPU and monitor technology is getting improved quickly, I think you're giving some incorrect info. Ultra wide 1440p monitors cap out at 100hz right now, not 144hz. The currents cards are pushing the 100hz ultrawides pretty much to their max and the 1080ti will 100% any slack left. 4k is possible past 60hz and a single 1080 is doing fairly well at 4k as is. 1080s in SLI can easily push a 4k monitor past 60fps and Asus is releasing a 4k 144hz monitor around Q3 of this year because of that. The tech is moving fast but you're exaggerating quite a bit on how hard it is to push these new displays.

I have to disagree, there are couple consumer grade 1440p 144Hz monitors (FreeSync) - ASUS MG279Q, Acer Predator XF270HU and even 165Hz one - Acer Predator XB271HU (G-Sync) all IPS. There are also VA Ultra Wide panels like BenQ XR3501 and Acer Predator Z35 with 3440x1440px and 144Hz. Technology in this area is recently progressing with decent speed.

None of the ultra wide 1440p monitors have 144hz. Almost all of the models you listed are 16:9 monitors and the one ultra wide is not 1440p. I agree that the tech is progressing but this generation of GPUs are pushing them quite well.

Why is your focus on ultrawide monitors? I'd bet most gamers do not use them for various reasons. You may have one but it is not the standard by which to gauge the viability of the GPU market. For example, Acer has a 240hz gaming monitor out now.

Two reasons: first, the earlier post specifically called out that, "...ultra wide 1440p monitors cap out at 100hz right now, not 144hz."

Second, it's all about pixel count. While 4k is still miles ahead of even the 3440x1440 ultra-wide resolution, that resolution represents nearly as big a jump in pixel count as the jump from 1080p to 1440p.

The goal is 4k at a minimum of 60fps. Consistent 100 hz or even 144hz on an ultra-wide 3440x1440 monitor represents a solid step in that direction.

BenQ XR3501 and Acer Predator Z35 are 2560x1080px, not 3440x1440px. The other three are 2560x1440px, not ultrawide 3440x1440px. Parent is correct that fastest 3440x1440px displays available today are 100Hz.

4K is not really possible past 60 FPS with current games on highest settings. And those are what the target group of gamers want, I see that basically every day.

For an example, take the latest Deus Ex: http://www.techspot.com/review/1235-deus-ex-mankind-divided-.... It is also a good example for the next statement: The heaviest games don't even get 60 FPS on 1440p, on Ultra the average with a GTX 1080 is 43. 4K is at 24, basically unplayable. Even if you were to use SLI, which is by now pretty much agreed upon to be more a hassle than worth it, it wouldn't be at 60 FPS. And that disregards that 2x1080 are/were 200% the price of a single GTX 1080 Ti, and won't be close to getting 200% the performance.

You can see that as you want, but I can pretty much guarantee that gamers, at least the segment of gamers that would even consider investing hat much into a gpu, will absolutely sprint to get a GTX 1080 Ti, if the performance increase is real. They need it for VR + 4K, or at the very least believe so.

As someone who plays things at 4k on my 1070 at home, let me add that things still look freaking amazing at 4k, even without Ultra settings. You can usually turn off antialiasing (sweet), and there are some effects that you probably might not notice (or care about) compared to speed.

The best part is, in two years (or four) when you buy a better card, all the titles that are currently new will tend to look about as good as 2-year-old titles look now. ;)

I have a 3440x1440 at 95hz (my Acer Predator X34 didn't quite meet the 100hz claim..), and 2x 980s. One of the 980s isn't fast enough to drive it properly; two work fine, but I'm almost always having SLI issues it seems. Therefore the 1080TI will be a massive improvement to me, especially as I run 2x 1920x1200s around the 34" and would like to use frameless windows - which essentially reduces the 2x cards to 1x (SLI only works in fullscreen). For example Elite Dangerous will start to stutter when only using one of the cards.

I've crunched the numbers and the 1080TI will essentially offer the 980 SLI performance at its best - and that's before the extra RAM and Pascal features come into play - as well as the reduced heat levels etc.

So count me in, especially when Vega comes out and presses the prices further south. (Alas my monitor uses GSync, so that won't be an option for me.)

FWIW I'd like to mention that the 34" screen is completely brilliant for programming (Visual Studio), which is what I use the setup for most of the time.

Please try this in the real world.

You can't get any games above like 30 fps on 4K monitors even without maxing out graphics options on a $350 card today. Add multiple monitors... slows to a crawl. You can hear the fans working to keep up with non-gaming tasks...

While I do feel like noticeable CPU performance enhancements have mostly plateaued, I think we are 4-5 years away from affordable and good 4K graphics cards. The choices on the market at present aren't all that amazing. You either pay a lot for meh, or a fortune for acceptable.

Nothing on the market today is like, "OMG it handles anything we throw at it without breaking a sweat..." And that's fine... it's usually 2-3 years after a game comes out that I can run it at max settings.

SLI/CF is a huge hack - only allows true fullscreen, does weird tricks to render on both GPUs, occasionally gets glitchy results and far more crashes. You do not want to use SLI unless you have no other option.

4k@60 gaming on a single card is an excellent goal. I'm running a single 1080 for this purpose at the moment and on many games it struggles and I have to reduce options significantly.

The 1080Ti should be performant enough to run 4k@60FPS on most games on a single card. The 1080 was close, running ~45-50 FPS, but this should push it over that edge.

Then there are the people who want 4k@144 and stuff who'll be running 2 of these in no time and still not getting the numbers they want...

Hopefully within a few iterations 4k@60 will get down to an affordable level. I just really want to go back to buying $300-500 cards instead of $1k cards and this means we're on the way.

If your life depends on having a 1440p screen at 144Hz you are not your typical gamer and you are doing it for no reason other than because you can.

Get a grip man. GPUs are not struggling. People are just demanding a lot from them because reasons.

I have used 4k for games for years and have never had trouble getting 60fps in every game.

With a 1060, when I really started gaming, it was pretty hard to have very good settings and get 60fps. Overwatch on Ultra ran at about 50fps (100% render scale), GTA 5 on the "nvidia optimized" settings was almost always 60fps but would drop down to 30fps sometimes. With a 1080, everything is always 60fps, even on Epic with some modifications (fog distance I think has the biggest effect). My attempt to max out the settings to just get 60fps has led to slow framerates (30-40) during hero selection and the "play of the game" intros, though. Only sometimes, it's very strange. (With the nvidia-optimized settings, this doesn't happen, though. But the graphics aren't quite as good in-game.)

Overall you should basically be able to pick any GPU and play any game at 4k. I would like to get another monitor for 1080p/1440p at 144Hz, but don't have anywhere to put it, so 4k@60 is enough for me. IPS panels are nice for everything except gaming, so I live with the compromise when playing games. Screen refresh rate is not the limiting factor in my ability, not by a long shot.

> I have used 4k for games for years and have never had trouble getting 60fps in every game.

Try Battlefield 1, or some other last-gen game (I believe Rise Of The Tomb Rider is also in this category). You won't get 4k60 on that one without a Titan X or a 1080 Ti.

That is, with the image quality settings maxed out, of course.

Yeah, I don't have Overwatch or GTA V completely maxed out. They both still look pretty spectacular, though.

Got the old Titan X. Serious Sam VR gpu speed detection: medium. feels bad.

Even dual 1080 GTX cards can't max out settings on the VR games currently available for Oculus / HTC Vive.

As for traditional usecases, I have a 3x monitor setup ( 2K@144Hz/4K@60Hz/2K@144Hz) and my 1080 GTX can't max out everything smoothly while I stream/record high-end games.

I would love it if all this was just vanity, but its my job. This stuff is an expense I'd happily avoid if possible. I don't own any nonsensical RGB lighted cases or non-essential peripherals.

Out of interest, are you handing off the encoding/streaming work to a separate device, or is that on the same PC?

That's definitely true for some, as a quick look at all the "specs avatars" in PC gaming forums confirms.

Completely disagree. A single 1080TI will finally be "good enough" for a lot of high resolution / high frequency use cases where you had to go SLI before.

I find it useful to multiply resolution with refresh rate to arrive at a number that indicates the number of pixels being pushed per second:

  1920x1080 x60  =   124,416,000
  2560x1440 x60  =   221,184,000
  3440x1440 x60  =   297,216,000
  3440x1440 x100 =   495,360,000 
  3840x2160 x60  =   497,664,000
  2560x1440 x144 =   530,841,600
  3840x2160 x144 = 1,194,393,600

So there you go - a maxed out 34" ultrawide has just about the same requirements as a 60hz 4k monitor. Yet a normal 27" 144hz will out-require both of them ... and they come in even faster variants yet!

Edit: And then you start seeing 144hz 4k screens; you will still find yourself wanting with a single 1080TI.

Demonstrably false, 4K 60fps gaming on max settings on most games (1080p@60fps is nothing on most high end GPUs) is still not really possible, and a 1080Ti probably won't achieve it either since the Titan X wasn't quite able to.

Also, VR gaming can never have enough GPU power, because supersampling increases the fidelity by a lot (first hand experience)

> Demonstrably false, 4K 60fps gaming on max settings on most games (1080p@60fps is nothing on most high end GPUs) is still not really possible, and a 1080Ti probably won't achieve it either since the Titan X wasn't quite able to.

You literally just argued why it is demonstrably true. If a Titan X, Ti, or standard 1080 can get to 4K 60 on max then buying an Titan X or Ti is nothing more than bragging rights.

Nobody is arguing that the Ti isn't more powerful, just that that power likely doesn't buy you anything specific, all you've done is show how that is true.

What? A 1080, 1080Ti, Titan X isn't "enough". So the closest you can get to "enough" is worthwhile.

This might be the first sub $1000 card to drive games at 4K above 60fps, so that's kind of cool. Considering that there are a few 4K 144Hz IPS monitors releasing this year the card lines up nicely.

I believe there is a subset of gamers who spend this kind of money for cultural reasons. But I build expensive beasts once and drive them until they run into the ground. My dual 690s handled "everything I could throw at them"[0] for years and years. I only just upgraded to dual 1080 FTW editions (also very expensive) and expect to run those for quite a few years as well.[1]

[0] Caveat: I only ever run a single monitor on my gaming rigs. [1] Turns out I get VR sickness something fierce, so VR won't really be a driving need for me.

Titan X seemed to fit between the Tesla's used in business applications and the 10x series used for consumer gaming - prosumers doing video and rendering on workstations.

I'm glad NVidia chose to canibalize that market rather than artificially constrain the consumer series.

Wasn't it Intel that did this with the Celeron's at some point to preserve the higher-end workstation market for performance? iirc they underclocked some processors that outside of L1/L2 cache weren't so different to the much more expensive Pentium 4/Xeon or whatever.

How does this stack up against the Titan X for ML applications? Is the extra 1gb or ram critical or will this be a comparable (or even greater) offering?

I'd buy the 1080 Ti instead. Titan XP is near double the cost! 1 GB extra isn't worth it.

Uncharacteristically for NVIDIA, it maintains the 8INT mode, so pretty damn well...

The difference between 11gb and 12gb isn't meaningful for most users of ML.

Yes, there are problems where squeezing in a slightly larger model than 11gb would give slightly better results; but that size of problem also would generally require a lot of computing power, at that point you're not comparing specs of a single card but benchmarks and scaling for clusters of multi-gpu machines.

I'd buy it for SLI since I already have a Titan X and was waiting for the price to drop.

SLI? Can't you put 8x or 16x Titan Xs together?

[NVIDIA Employee disclaimer]

Not in SLI, no. SLI is a technology to have two GPUs act as one, by syncing among themselves. When you have two GPUs in SLI, your CPU program will generally see them as a single GPU with (almost) twice as many cores and twice as much bandwidth, but the same amount of memory.

For this to work, the GPUs need to be very similar (i.e. you can't SLI a TitanX and a 1080).

You can, however, put many[1] different GPUs in the same system, and then the onus is on the CPU program to properly manage and send work to each one separately. This is not SLI.

Generally, SLI is useful for games where the program assumes "a GPU" and sends work to it, and you want to have more performance than your single card can provide. For compute/ML, you're much better off just using each card directly.

[1]: Don't quote me on this, but I believe up to 8x is supported, above that is uncharted territory.

Is it possible and would it make sense to use an SLI Bridge without using SLI to boost the cross-card data transfer rates when doing compute workloads?

Sorry, not sure exactly how SLI bridges work - it may or may not be possible to selectively sync only parts of video memory.

In cases where you want faster cross-card transfers and are willing to mess with HW configurations, there's NVLINK.

Wiki: https://en.wikipedia.org/wiki/NVLink

PR piece: https://blogs.nvidia.com/blog/2014/11/14/what-is-nvlink/

Amazon is offering instances with 16 Tesla K80 GPUs. I don't know how that is realized under the hood, though.

SLI is only for realtime rendering with Direct3D and OpenGL. Tesla GPU products are intended primarily for CUDA and OpenCL use, which have always required the application to be aware of the underlying hardware configuration. There's no need to pretend that the 16 GPUs are one super-powerful accelerator device.

Some of the high end Xeon systems have gobs of PCIe lanes. If you have a four CPU socket system, you can hang four x16 PCIe cards off of each processor.

Or get specialized board with PCIe switch ie. http://www.cirrascale.com/blog/index.php/welcome-big-sur/

so GPUs get better bandwidth (P2P etc).

4CPU sockets !=> 4x x16 cars. It always depends on the number of PCI lanes for each processors. Check i.e. these 2 E7 Xeons: http://www.intel.com/content/www/us/en/products/compare-prod...

Both have max 32 PCI Express lanes - so you can theoretically hang max 2 PCIx x16 cards off each CPU, but as few of the lanes is reserved for other peripherals, in 4GPU/CPU setup they will practically run at lower speeds, ie 8/8/4/4. However, using system with PCIe root complex [1] can improve the GPU<->GPU communication speed.

[1] https://www.microway.com/hpc-tech-tips/pci-express-root-comp...

They're treated as independent compute units and the host program load-balances compute work between them. You can even do P2P memory copy or access between your CUDA devices without going through the CPU. See https://www.nvidia.com/docs/IO/116711/sc11-multi-gpu.pdf for a high-level overview.

I understand there was a recent shift away from such practises at nvidia, but am I correct in saying that the 3-way sli bridges do still work with the newest cards?

No.

NVIDIA said the 10-series can only do dual-SLI at most (two cards), nothing more.

Sorry for asking, but you might have a better insight. I have two questions, which you might answer:

- Is it possible, officially supported way, to have both GTX and Quadro at the same time in the machine? I prefer GTX for rendering speed (Redshift renderer), but I need 10-bit output Quadro has which GTX doesn't have.

- Are there GTX (1080 TI in this case) cards out there which don't take double PCI space? I don't need multiple outputs and I can hook them up to the water block, if needed. I need as many cards in a single workstation case as possible for rendering. I've seen people saw/solder off stuff from cards in order to get at that, but not something I would do personally. Ideally I would prefer to have eight 1080 TIs in a single machine along with a single (modest) Quadro for 10-bit output to three monitors - are there even motherboards that could support that?

Note that I'm looking for workstation / deskside solution, not server 747-fan-sound-behemoths.

GTX cards do have 10-bit output (on Linux at least).

I would like 12-bit output, but that's not possible due to limitations in X11.

Is that a recent development? One of Quadro's feature over GTX was/is 10-bit output. No way around it if you're using a 10-bit monitor like EIZO ColorEdge or whatever.

My GTX on Windows also claims to output 10 bits. From some playing around in Photoshop, it seems like the monitor I have does not actually use the extra data. (It asks for it, but either doesn't receive it, or doesn't process it properly.)

You can use PCI risers to give yourself some more flexibility as to how your cards are plugged in. However, please make sure you have enough PCI x16 or x8 slots. If you're not running a server motherboard, I highly doubt you have enough PCI lanes to fit more than two or three cards.

"You can, however, put many[1] different GPUs in the same system, and then the onus is on the CPU program to properly manage and send work to each one separately. This is not SLI."

Interesting that you mention this as I've been searching for an answer before I build a ML rig and embark on learning it. Is there any benefit for ML performance if I put a GTX 970 and a 1080[ti|x] in the same machine? Just trying to figure out how to re-use spare parts.

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