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AMD optimized App

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Jason G:
Those are slightly better middle ground comparisons, thanks arkayn.

KarVi:
I have to reply to this thread.

Allthough I'm very pleased with the results of the optimizations, and have the greatest respect for the effort done by the optimizers here, I still beleive much emphasis is put upon making the apps fast on Intel architecture, and less upon AMD. This is understandable, seing how Intel has 75-80% of marketshare, and the tools they have are better.

Still I have to wonder what performance AMD chips could have, if an AMD specific build where made where optimizations where made to take advantage of AMD's strenghts, and avoiding the weakneses.

I once read this at Aces hardwares forum (a very good technical forum) about AMD and optimizing for it:

Quote:
I once had the opportunity to discuss online about that with several people, including some AMDers. AMD is desperate because they can't break the cycle of Intel's C++/Fortran compilers which are turning to be venom against AMD cpus much due to AMD's own design choices of late. Microsoft's compiler may help them IF coders care to create a code path for AMD.

AMD's L1 cache can work very well with FFT's and possibly compete with more expensive metal but it's still underutilized and adoption of adequate tools is going on slower than they predicted. AMD made the choice to equip their cpus L1 caches with neat features that Intels don't have and, of course, Intel doesn't care to optimize for. Prime95 worked like a dog with AMD processor until GIMPS adopted the prefetchw opcode for AMD's codepath along several other optimizations and since that, AMD's latest is the fastest clock-for-clock under Prime95. prefetchw is also useful to accelerate core-to-core coherency through the L3 cache.

Quote end:

Personally I know next to nothing about coding (once learned a little Turbo Pascal...), so I don't know how much work would be required for an AMD specific build, but if one was attempted, I would be more than happy to run lots of tests, to find the best solutions for AMD CPU's.

Jason G:
I will say once more, the astropulse builds are made on Microsoft visual studio, not intel compiler.  If something is unclear here, please enquire, alternatively the source code is available from the download section.

KarVi:
That wouldn't help me any, since I can't read code.

You seem to be annoyed of me posting my worries. I don't understand the reaction. Though I may seem to be criticizising, my hope is to be helpfull and constructive.

There have been several Intel only builds, what would be wrong with an AMD only build? Do you use "prefetchw", and if you do, does it take the larger L1 cache into account? How about looking into SSE4a, or some of the 3DNow! instructions. Perhaps and only perhaps, one or two of the instructions therein could be of benefit?

Would you agree that the possibility exists that different code paths than the ones used, could perform better on AMD hardware? Why not try? This is only a suggestion, if the workload needed to create these builds, is of such magnitude that it would be counterproductive for the general optimization, it should just be left alone.

Jason G:
I am indeed annoyed, because you are using our development site as a platform for your rant oriented around AMD Vs Intel, false information, and completely ignored our last discussion on the issue.  Take it elsewhere.

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