AMD Radeon HD 6000 Gallium3D Attempts To Compete With Catalyst
Phoronix: AMD Radeon HD 6000 Gallium3D Attempts To Compete With Catalyst
Open-source code supporting the AMD Radeon HD 6000 "Northern Islands" GPU hardware has been available since January, but only in the past few days has this Linux code matured to the point of being stable and useful for testing. In this article are our first benchmarks of the AMD Northern Islands and Cayman graphics processors using the open-source Mesa Gallium3D driver and comparing its performance to AMD's proprietary Catalyst driver.
The CPU actualy is the bottleneck and it will stay to be a big part of the driver unless those cocks at HTC/SGi release some stupid patent licenses....
The CPU bottleneck is less code that's running in the driver, and more making unnecessary kernel calls resulting in slow context switches, unnecessary flushes of data between the GPU/CPU, passing huge structures of data around that aren't very cache friendly, etc.
None of those things are likely to be affected very much by a change to the compiler - they need to be fixed algorithmically.
A software rasterizer, on the other hand, could see benefits. As could something like the old hardware that does vertex shaders in software and the rest on the GPU. Then again, these days that's mostly done by LLVM anyways so that generated code probably wouldn't be much different either.
Oh, and what patents are you referring to? The only two i know about are the floating-textures one (which is a feature, not anything performance related) and the S3TC one (again, just a new feature, and not anything that would impact performance one way or the other).
Last edited by smitty3268; 07-14-2011 at 03:00 AM.