I thought it wasn't agreed on that LLVM was the best longterm solution (for current cards) either.
Originally Posted by Ericg
Yeah, I don't think there's a hard agreement about that. LLVM seems to have trouble with VLIW architectures. And as Vadim pointed out, another problem is the complexity of LLVM. Code generation is bad in many cases, but it's hard to figure out what goes wrong and why. This is much easier with a small, dedicated codebase like r600-sb.
Originally Posted by curaga
Michael, when you test r600-sb, make sure you include Heaven and Doom3 on higher quality settings. Pixel fill-rate is directly dependent on Frag shader optimizations.
It is pity you will have redone AMD part of 15-way comparison again.
LLVM's latency is another point against it - it takes much longer to compile a shader using llvm than the current compiler. A long pause in the middle of a level isn't nice.
(bad game design not to load all shaders at load time, but many games do so)
I get the impression that there isn't a moment when Michael isn't benchmarking something. By the time he completes something, another new version of something gets released so I'd imagine it gets pretty hard to keep up (though, I figure most of it is just waiting around).
Originally Posted by Drago
I've done some ad-hoc comparisons with WebGL demos from the "chrome experiments" site, and R600_DEBUG=sb gives me a solid 50-60% FPS boost with demos that use heavy-weight shaders (blur, raytracing, etc.). Very nice. The Unity dash blur also seems to be noticeably faster.
Looking at the statistics (R600_DEBUG=sb,sbstat) this does not surprise - r600-sb optimizations in many cases brutally reduce the length of the shader program, the number of GPRs used and the number of ALU operations. I haven't noticed any bugs yet.
Last edited by brent; 05-01-2013 at 11:24 AM.
THIS. IS. AMAZING!
Originally Posted by pingufunkybeat
Congrats AMD and every developer involved!
The PM is really one big cons of the FOSS driver atm, let's hope it turns out as good as fglrx so I and many people can say a final goodbye to closed drivers.
Last edited by Azultra; 05-01-2013 at 01:20 PM.
Looks more likely I'll switch back to the OSS drivers for my 4670 card. Waiting for the benchmarks from Michael to make my decision.
Now we just need better opengl compliance and power managements and then the OSS drivers will be able to replace fglrx for the majority of users.
Hit a few snags trying to build it, so no test results from me today.
The difference for your 4670 is 3.1 vs 3.3, or mainly geometry shaders - hardly an often used feature.
Wow, Vadim replied in less than an hour, fast customer service that
It built now, but the results are pretty bad on my RV710 (HD 4350).
glxgears has wrong output:
Also some of my private apps regressed badly, 28 -> 7 fps, visual errors, and a pegged cpu core.