Nvidia relesed an alpha or beta driver that contains CUDA 5.1 for the 6xx cards(driver version 302.59) Kepler based gpus are supposed to perform better under cuda 5 - at least in computing department. All that’s left is to make cycles work with these drivers (not sure if it’s feasible though) and check render speeds using kepler gpus.
Any concrete information to back this up? I might soon purchase a GTX580 but if the CUDA performance of the 680 increases substantially I might wait a bit. But I doubt it will.
I dug this information in octane forum - it’s reliability is yet to be proved and I thought blender artists is the perfect place for this - lately there were some tries to render benchmark scene witch amd cards backed with the latest beta drivers - with worse or better results. The alpha/beta drivers with cuda 5.1 are here - all we need is some guy who can wrap his head around all this kernel compiling stuff :eyebrowlift:
The CUDA 5 SDK isn’t publicly available yet. I’ve applied for a developer account on their site so maybe I’ll be able to provide a build later on. Apart from that I think DingTo is the right guy to deal with this. We also need someone with a GTX680 to test.
Let us know should invidia provide You with the newest sdk. User by the name of swidd is in possesion of gtx680 - he posted results in the benchmark thread - hopefully he will cooperate :eyebrowlift:
What is the current recommendation? Should I go for the 580 or get a 670? If right now the performance of the 670 is at least comparable to the 580 I can live with a gig less memory…
So: do the Kepler GPU’s work with Cycles at the moment and are they an alternative to the 580?
Afaik the kernels compiled with the newer SDK (required by Kepler) cannot be considered stable yet. I believe the older SDK is still used for pre-Kepler gpus in 2.63 release. This all still needs more testing.
As far as performance goes, it seems like nobody has benchmarked a 670 yet. The 680 was around 20% slower than a 580 from what I saw in the benchmarks thread.
Hm, ok, so I don’t expect the 680 to get that massive of a boost by the new CUDA SDK. Even if it was 20% faster than the GTX 580 it still cost about 25% more. I think I’ll go with the 580 this time. Always the same with hardware, the next revolution is around the corner (at least that’s what they want you to believe).
I did some tests with building current Blender trunk with the 4.2.7 Toolkit, which still causes some weird freezes etc (I am on a 540 gpu though). As soon as there is a SDK for CUDA 5.0 I will make a build with it.
I’ve gotten accepted into the Developer Zone, so here is a build built against the CUDA 5 SDK. I could only test it on my GTX460 and I did not notice any performance difference. If by chance you’re getting any messages about missing DLLs, try copying the DLLs from a blender release build.
Great news. Now if only someone in possesion of kepler gpu would check this build out …
Unfortunately it’s only a x32 build, these are quite slower and most people with a Kepler card will use x64 OS I bet. 
It ain’t half bad:)
Mike Pan’s BMV benchmark:
gtx470 (overclocked): 37.10s
would be even less but for some reason after rendering compositing takes a little bit longer than what I get from recent builds - still rendering alone beats every build I’ve tried so far by a few seconds - lets hope for the best …
As far as CUDA performance goes, I can’t see a difference. BVH build times are faster on x64 though. In any case this is just for testing (I don’t have an x64 setup for MSVC2008) and there’s no harm in running 32-bit applications on win64. I had hoped you’d provide some builds, though 
I see, I didn’t pay that close attention. Indeed there is a new compositor for 2.64 and people have mentioned it is slower in some cases.
EDIT: I have tested CUDA4 vs CUDA5, and the CUDA5 build was only 1 second faster on a GTX460.
donkeyhot (gtx680 owner) will test new cuda 5.1 sdk but he will need linuks64 build so DingTo, Zalamander would You be so kind?
GTX 680 owner report
Mike’s BMW
GPU - 
Which drivers should I use? I downloaded the latest official drivers and black screen
Currently 301.42. Downloaded some dev beta drivers…
OS Win7 x64
tried Nvidia’s beta 302.59. Still black
Hm, did you use this build?
http://www.2shared.com/file/IKxFPgkQ/win32_r46979_cuda50.html
Cheers, mib.
Yup, that is the build I from this thread. Once I remember how to popup the console I might be able to say something more.