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With 8 Cards, Wolfenstein Ray Traced 7.7x Faster
An anonymous reader writes "As Slashdot readers know Intel's research project on ray tracing for games has recently been shown at 1080p, using eight Knights Ferry cards with Intel's 'Many Integrated Core' architecture. Now a white paper goes into more detail, documenting near-linear scaling for the cloud setup with 8 cards, and gives details on the implementation of 'smart anti-aliasing.' It will be interesting to see how many instances of Intel's next MIC iteration — dubbed Knights Corner, with 50+ cores — will be required for the same workload."
it honestly looks like an old game to me, yes there are some impressive features, but I really have to look for them in the images, something that is not going to happen at 60Hz (and if its not running at real speed who cares, that is a movie which can take its sweet ass time rendering frame by frame)
so, how does it stack up against a Riva TNT2?
(ducks)
...which is why it's easy to scale up. Thus the speedup isn't that impressive. Scalability on tightly coupled apps would be much more interesting.
Computer simulation made easy -- LibGeoDecomp
Wolfenstein is an old game. The ray-traced version is being used as a "Utah Teapot", a standard object to develop and compare rendering techniques.
Science is all about firing a drunk pig out of a cannon just to see what happens.
So you're implying that intel, a company notorious for building shoddy GPUs, used Wolfenstein for their demonstration not because Wolfenstein is the latest and greatest game that requires good hardware, but because it shows their cards in a good light?
Yeah, that makes sense.
Not to mention that those 8 cards probably don't have as much raw pixel pushing power as a pair of SLI or CF cards from the other guys, really not that impressive. Frankly Intel should have tried to buy out Nvidia years ago, the thing that gimps their chips more than anything is the crappy IGPs, instead they shoot themselves in the face by killing the Nvidia chipset business thus making Atom completely worthless. With ION it was actually a nice little unit but with Intel IGPs Atom is horrible.
That is one place you really have to give AMD credit, they saw the direction the market was going with low power mobile devices and bought ATI which makes excellent chips and ended up with Brazos, a dual core with HD graphics that sucks less than 18w under full load. I mean sure 8 cards might be nice for a render farm, but how many are gonna be willing to pay that electric and cooling bill with the prices constantly going up?
While I appreciate the effort Intel's answer to graphics has never been very good and if they need to throw 8 fricking cards at it I don't even want to know how many watts this sucker is pulling. The future is obviously mobile and while Nvidia has tegra, AMD has brazos, what's Intel got that can compete with that level of graphics in that small a wattage envelope?
ACs don't waste your time replying, your posts are never seen by me.
Actually, I remember Intel doing a lot of work on a new Wolf 3D engine specifically designed for excellent scaling, rather than raw performance on a single GPU.
This isn't Wolf3D. It's a much better engine (especially if you are Intel), with Wolf3D content.
Spot on! ION was the best thing that ever happened to the Atom platform. Really, it was the only thing that made it into a usable HTPC or ultra-low-power desktop. They really need to stop shitting down NVidia's throat because they are precisely the kind of aggressive, performance-driven company that would fit alongside Intel's model.
-Billco, Fnarg.com
Note that these are raytracing cards, not rendering. Raytracing is a very different technique which can do cool effects like refraction through glass (shown in the chandeliers and scopes), jawdropping water, and realistic lighting effects that rendering cards simply cannot do.
It's also much more demanding on hardware. One of the big drawbacks is it requires a lot of scattered reads out of memory making caching much less effective. You need tons of bandwidth to low latency memory to make it happen. We're still a very long ways out from having this possible in reasonably-priced consumer GPUs.
Rag on Intel for their integrated graphics if you want (though I consider them a good non-gaming graphics chip with very good open source support), but these cards are not related to those in any way. These are full-featured x86/x64 processors with 32 cores per die. In other words, they created a 256-core system capable of software-raytracing the whole thing at high resolutions.
That is quite an accomplishment, and rest assured, it is top-tier performance in the raytracing world. This isn't meant to be a practical gaming system; this is pretty clearly being done by Intel to show off the benefits of their many-cores processors, and it is an impressive show.
To the GP: They're using Wolfenstein because it's one of very few games that has a ray-traced variant, and it exists only because Intel created it as a testbed. More on that here: https://en.wikipedia.org/wiki/Wolfenstein:_Ray_Traced
The problem with these demos is, they use ray tracing like we did in 1980 (i.e. Whitted style). All computations are highly coherent and efficient. As soon as you want to have more natural rendering, with diffuse illumination etc. Parellization doesn't scale proportionally anymore. Rays become heavily incoherent, memory access scatters and you get cache misses etc. So the real feat would have been if tey show 7.7x speed with diffuse global illumination.
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Apparently this is the newer wolfenstein games; I wanted to see what 8 GPUs worth of fancy effects could do to the original pre-Doom Wolfenstein :(
I mod down anyone who says "I will be modded down for this", regardless of the rest of their comment
I believe you're mistaken. Raytracing IS the technique where you're tracing light much the way it happens in the real world. The techniques usually used in GPUs are quite backward. It hasn't really been all that downhill, though; they've gotten pretty good at faking a lot of the effects, but when it comes to things like shadows, local lighting, radiosity, and refraction, Raytracing is where it's at.
Examples:
https://upload.wikimedia.org/wikipedia/commons/e/ec/Glasses_800_edit.png
http://hof.povray.org/images/chado_Big.jpg
http://hof.povray.org/micra1_09.html
http://hof.povray.org/images/warm_up_Big.jpg
http://hof.povray.org/images/kitchen.jpg
All of those are from POV-Ray. There are plenty more in their gallery over here:
http://hof.povray.org/
Feel free to send some counterexamples of other techniques doing it better.
Wrong. Nearly the entire raster pipeline would be ignored for ray tracing, and you don't really need a lot of shading units for the rest (don't need to multitexture in the background and whatnot). The main use for the GPUs in ray tracing would be collision detection, which could be written into shaders as long as the entire scene was loaded into each GPU's memory, so Wolfenstein is actually a good choice - a large scene would have problems because of memory constraints. Ray tracing works very well with lots of parallel CPUs, but usually is memory constrained (dependent on memory access more than anything else) in that scenario, so splitting it off onto multiple GPUs is a way to remove that constraint, but basically it still works like a lot of parallel CPUs accessing the same scene in memory.
So what? It's essentially same end result with orders of magnitude less computation from wasted photons.
Where do you get that raytracing is "some of the least realistic"? It's one of the most realistic techniques that's actually in use, far better looking than anything that's currently done in realtime.
It's also much more demanding on hardware. One of the big drawbacks is it requires a lot of scattered reads out of memory making caching much less effective. You need tons of bandwidth to low latency memory to make it happen. We're still a very long ways out from having this possible in reasonably-priced consumer GPUs.
Yes, it is exactly what Intel Mic card are awesome for. They are generic x86 core with 4-way SMT and a buttload of memory bandwidth. I worked with Knight Ferry prototypes and studied the scalability of the worst case of algorithms for scattered memory access: graph algorithms. (The paper will be published soon but the preprint is available at http://bmi.osu.edu/hpc/papers/Saule12-MTAAP.pdf .) Basically, we achieve close to optimal scalability on most of our tests.
These MIC card are designed to scale in good cases (compact memory and SIMDizable operations such as dense matrix vector multiplication, or image processing) but almost in the bad cases (lots of indirections, accessing caches lines in pathological scenarios such as sparse matrix vector multiplication, graph algorithms.)
I am excited to get a hold on the commercial card (we worked on prototypes) to make a CPU/GPU/MIC comparison.
Try the new Brazos friend, especially the E350 and E450 units, they are what Atom+ION USED to be. I have built several low power office units and HTPCs out of them and was impressed enough by the performance i sold my full size laptop for a 12 inch EEE with an E350. i get nearly 6 hours watching HD videos, never gets hot, video is smooth, hell I even play L4D and GTA:VC (I could play the newer ones but don't care for them) on it and it doesn't skip a bit. Also because AMD isn't in bed with Microsoft or trying to force you to upscale there is no artificial limits on their chips, most will run 8Gb of RAM and the lowest you'll find on max RAM is 4Gb, compare to Intel's 2Gb limit and 10 inch screen mandate. Check out Tiger and Newegg and you can find several units where all you do is slap in the HDD and RAM and you're good to go and these babies can be passively cooled and just sip power.
But what happened with Intel and Nvidia is just a classic example of what happens when a company gets too greedy. Intel couldn't stand the thought of not getting 100% of the chipset business and instead of seeing the added value having a powerful GPU could bring to a weak chip like Atom they killed the entire line and made the chip all but worthless. All my customers that bought non ION Atom units quickly returned them because they were just too damned slow, the units even under XP just felt like they were constantly dragging. I don't know how many time I had an Atom unit brought in by a customer asking "Can you make this any better?" only to have to tell them "Yeah, sell it and get an AMD because this sucks". My EEE has 8Gb of RAM and came with Win 7 HP X64 and runs that full OS as well as any desktop.
Oh a word of advice, if you do try a Brazos unit get "Brazos tweaker", its a free download from Google Codeplex and by dropping the voltage a little you can squeeze even longer battery life or get an even quieter unit. I managed to drop my EEE down 200Mhz at idle and 5% voltage under load which translates to nearly an hour on my 6 cell. really a great chip though, often cheaper than Atom alone yet gives better performance than Atom+ION, makes a great HTPC and both Tiger and the Egg have some really small passive units, just a great chip.
ACs don't waste your time replying, your posts are never seen by me.
That Intel is not just some small outfit, and they are the ones who want to push this change from rasterization to ray tracing. Rasterization works great and looks good and is what run well on all the GPUs out there today. Makes AMD and nVidia happy, they make billions doing it. Intel is unhappy, they want you spending less, or rather none, on those products, more in Intel products. So they are on about ray tracing. Something that GPUs aren't as good at.
Well guess what? To convince people the change is worthwhile, they've got to show it as being better. I'm not interested in something that requires expensive new processors unless it gives me a benefit. So let's see it then. Let's see a ray tracing engine blowing rasterization out of the water.
It's not like they can't hire someone to do some work on it. Look at the demos that come from places like Uengine and 3DMark. Let's see something that makes us go "Wow, that is sweet."
Instead, we see lame demos that don't look much if any better than the original (and that being an old game) and on the rasterization front we see photorealistic skin rendering by a few guys at a university that you can run on your PC at home http://www.iryoku.com/separable-sss-released.
You can see why maybe people are not so impressed with Intel carrying on about raytracing as the future of games.