Posted 23 Jan 2017 by
Beyond
I found why FMA version crashed. I compiled windows FMA version with target CPU architecture set to Haswell, and gcc enabled AVX2 which is not supported by AMD Bulldozer CPUs so app crashed with message "Illegal Instruction". But SSE2 version crash is surprising, it is compiled with the same options (target architecture: core2). Could you check again to make sure that it crashes, and provide me link to failed task? I would like to check error message.
I have recompiled and uploaded FMA Windows version, now it does not use AVX2 so it should work fine. I also uploaded separate AVX2 versions for Windows and Linux 64-bit. Could someone with sufficiently new CPU run some benchmarks with test data on AVX2 and FMA versions? I wonder if there is some performance improvement between AVX2 and FMA versions.
I'm draining the queue on one of my AMD FX-8320E machines now. Will install the fixed fma version and test.
Posted 23 Jan 2017 by
Beyond
But I´m getting compute errors with the new SSE2 and FMA App. Only AVX ist working very well on my FX 8320 (Win 10 64 bit). Keep on Your great work!
On my four AMD FX-8320E and 8310 machines the older fma app worked but not the new version. However the newest sse2 version is working fine (error free and validating properly) on all of those boxes and also on my various AMD Phenom II X6 CPUs, the AMD 5350 APU and the Intel Celeron 1037U. Haven't tried the newest avx as the previous avx version didn't test faster for my machines.
Posted 23 Jan 2017 by
Beyond
Thanks Daniel!
I tried the newest fma version and it crashed on a machine that worked with the old fma optimized app.
The new sse2 version worked on all my various CPUs and was over twice as fast as the previous optimized app.
To be clear, the new sse2 app is more than 2x faster on every one of my machines, even the ones that ran the old fma version.
Posted 14 Jan 2017 by
Beyond
Immediate failure. I tested on 12/25 and those WUs are out of the database. On most machines the avx app ran but wasn't any faster (often slower) than the sse2 app. In fact I found no machines on which the avx app was superior. The fma app was a little bit faster than the other 2 versions on my AMD X8 boxes.
Be aware you need a capable cpu to run those applications. Looking at your computers, ony AMD FX have both avx and fma, Athlon 5350 have only avx. however, they are not known to be excellent in these capabilities :)
Thanks. Pretty much to the point I was making. Looks like you're in the same boat. What CPUs actually use avx effectively? Comparative times?
Posted 14 Jan 2017 by
Beyond
You mentioned errors with AVX app. Are they problems with starting/running app, or validation errors? If with starting/running, could you provide me link to example failed WU? I would like to check if there are some details which may be helpful.
Immediate failure. I tested on 12/25 and those WUs are out of the database. On most machines the avx app ran but wasn't any faster (often slower) than the sse2 app. In fact I found no machines on which the avx app was superior. The fma app was a little bit faster than the other 2 versions on my AMD X8 boxes.
Posted 13 Jan 2017 by
Beyond
I checked your computers and found few validations errors, but no error reported by app or BOINC client that something was wrong. Maybe these are caused by that mysterious error mentioned by valterc before? I also saw this few times but on SSE version. That was on machine running 24/7 and BOINC configured with long task switch time, so these WUs were crunched from start to end without interruptions. One of them was also crunched by someone with my app and that for that person it was validated successfully, so it is even more interesting.
The only 3 validation errors I had were all at once on 1 machine when there was a power glitch. The problem I had with the non sse2 versions were on certain CPU types. They errored all WUs immediately, but it was a while ago when I was testing and the WUs are no longer in the database. The sse2 version runs fine on every machine I've tried so far (15-20 boxes for myself and friends).
Posted 13 Jan 2017 by
Beyond
So, with sse2, avx, fma, any modern computer will get the three applications and eventually decide which one is the best one...
Potential problem: some machines error the WUs with avx and fma while sse2 seems to work with everthing I've tried.
I've found that fma can be slightly faster than the sse2 version on some machines but the difference is small.
What OS do you use? AVX needs support on OS side too. List of supported OSes is here: https://en.wikipedia.org/wiki/Advanced_Vector_Extensions#Operating_system_support
All machines are Win7-64.
Do you have SP1 installed? AVX support was added in it.
Yes and all patches and updates.
Posted 13 Jan 2017 by
Beyond
So, with sse2, avx, fma, any modern computer will get the three applications and eventually decide which one is the best one...
Potential problem: some machines error the WUs with avx and fma while sse2 seems to work with everthing I've tried.
I've found that fma can be slightly faster than the sse2 version on some machines but the difference is small.
What OS do you use? AVX needs support on OS side too. List of supported OSes is here: https://en.wikipedia.org/wiki/Advanced_Vector_Extensions#Operating_system_support
All machines are Win7-64.
Posted 13 Jan 2017 by
Beyond
- stats on downloads page shows that 32-bit windows non-SSE version of my app was downloaded 12 times, so there is some need for it.
All that means is that 12 people might have tried it, not that anyone uses it. Some download all the versions and try them, or just DL them all in case they might want to later. I've tried all the 64bit versions on various CPUs but only the sse2 and fma were useful and even the difference between those was small.
BTW, THANKS MUCH for all the hard work!
Posted 13 Jan 2017 by
Beyond
So, with sse2, avx, fma, any modern computer will get the three applications and eventually decide which one is the best one...
Potential problem: some machines error the WUs with avx and fma while sse2 seems to work with everthing I've tried.
I've found that fma can be slightly faster than the sse2 version on some machines but the difference is small.