Is fma faster than avx on the Ryzen 1700?
It seems to be just slightly, though they are so close that it would take longer-term testing to be sure. I think it would be easier for the project to find the best extension for a given processor type, and just use it.
I'll drink to that. None of my machines ever get the fma version so I don't even have the latest executable to test. Looking at the current applications it doesn't even show an fma version for Windows. Maybe v1.10 was the last fma version? I wish we could just pick the app(s) we want to run through project preferences.
Reply
Quote
Looking at the current applications it doesn't even show an fma version for Windows. Maybe v1.10 was the last fma version? I wish we could just pick the app(s) we want to run through project preferences.
My Ryzen 1700 and 2700 machines are on Ubuntu 18.04, and yes the fma is version 1.10. But I used Windows earlier on an i7-3770, and it did quite well compared to Linux. But that one got only SSE2 and AVX. I think the latter was slightly faster.
I agree; let us select them and be done with it.
Reply
Quote
had to abort sse2 after 10 hours but with 442 days remaining. there were no other cpu tasks running other then this project. Looking HERE sse2 and avx had same problem but fma and an anon succeeded. wonder what the "anon" was.
Reply
Quote
valtercProject administrator
Project tester
Send message
Joined: 30 Oct 13
Posts: 623
Credit: 34,677,535
RAC: 1
Is fma faster than avx on the Ryzen 1700?
It seems to be just slightly, though they are so close that it would take longer-term testing to be sure. I think it would be easier for the project to find the best extension for a given processor type, and just use it.
I'll drink to that. None of my machines ever get the fma version so I don't even have the latest executable to test. Looking at the current applications it doesn't even show an fma version for Windows. Maybe v1.10 was the last fma version? I wish we could just pick the app(s) we want to run through project preferences.
The latest fma version for Windows (v1.10) was available only as a 'test' app, mainly because problems (crashes) with the earliest bios for Ryzen cpus. The difference in speed between sse, avx and fma are not so huge so we decided not to build the v1.11 fma version for Windows.
Reply
Quote
valtercProject administrator
Project tester
Send message
Joined: 30 Oct 13
Posts: 623
Credit: 34,677,535
RAC: 1
had to abort sse2 after 10 hours but with 442 days remaining. there were no other cpu tasks running other then this project. Looking HERE sse2 and avx had same problem but fma and an anon succeeded. wonder what the "anon" was.
"aborted by user" is not 'technically' an error, it's a user's choice. I agree that if I saw a workunit stuck at 5% with an estimated time for completion of days (even if the estimate were completely wrong) I would also be tempted to abort it. The 'problematic' behavior of the TCGA workunits doesn't depend on the version of the application.
The sse2 problem of some Ryzen cpu with the current application is a 'real' problem: the app crashes with an 'illegal instruction' error.
I just sent an e-mail to Daniel (the user who actually wrote the sse2 code) asking for hints.
Reply
Quote
had to abort sse2 after 10 hours but with 442 days remaining. there were no other cpu tasks running other then this project. Looking HERE sse2 and avx had same problem but fma and an anon succeeded. wonder what the "anon" was.
"aborted by user" is not 'technically' an error, it's a user's choice. I agree that if I saw a workunit stuck at 5% with an estimated time for completion of days (even if the estimate were completely wrong) I would also be tempted to abort it. The 'problematic' behavior of the TCGA workunits doesn't depend on the version of the application.
The sse2 problem of some Ryzen cpu with the current application is a 'real' problem: the app crashes with an 'illegal instruction' error.
I just sent an e-mail to Daniel (the user who actually wrote the sse2 code) asking for hints.
Hello again, I was not here for long long time :)
This looks like another Ryzen bug. This time CPU also jumps to address in middle of instruction, what must end in crash sooner or later.
I have reported this bug on AMD forum. Here is link to my post, it should be visible soon when moderator approves it:
https://community.amd.com/message/2890585
____________
Reply
Quote
This looks like another Ryzen bug. This time CPU also jumps to address in middle of instruction, what must end in crash sooner or later.
I have reported this bug on AMD forum. Here is link to my post, it should be visible soon when moderator approves it:
https://community.amd.com/message/2890585
The SSE2 problem for me (and Beyond) was only on the Ryzen 1700. The Ryzen 2700 is OK. Maybe you should amend your report?
Thanks for looking into this.
Reply
Quote
This looks like another Ryzen bug. This time CPU also jumps to address in middle of instruction, what must end in crash sooner or later.
I have reported this bug on AMD forum. Here is link to my post, it should be visible soon when moderator approves it:
https://community.amd.com/message/2890585
The SSE2 problem for me (and Beyond) was only on the Ryzen 1700. The Ryzen 2700 is OK. Maybe you should amend your report?
Thanks for looking into this.
Interesting. I have followed link on task info page to get info about CPU and OS, so looks that sometimes crashes occur on 2700 too. Unfortunately today this task page is deleted so I cannot add link here. Anyway, I will update my report that bug happens mostly on 1700.
____________
Reply
Quote
Interesting. I have followed link on task info page to get info about CPU and OS, so looks that sometimes crashes occur on 2700 too. Unfortunately today this task page is deleted so I cannot add link here. Anyway, I will update my report that bug happens mostly on 1700.
Never had SSE failures on my 2700, only on the 2 1700 Ryzens. AVX and FMA are bulletproof on all of them.
Thanks/Ed
Reply
Quote
I have to dig up this topic. This project is very limited in allowing the users to decice which app will run. It is all decided by whatever algorithm.
Now, I have a new CPU that would be faster with the avx version but my machine will not get that version, because the old CPU was slower on avx. The avx-FLOPS for my machine are outdated, but cannot become refreshed as I will not get avx tasks. This is a loop I cannot escape on my own.
Using an app_info.xml is a shitty workaround because it creates a new "generic local app"-profile on the servers statistics. I'd like to use the avx version the official way.
Reply
Quote
Now, I have a new CPU that would be faster with the avx version but my machine will not get that version, because the old CPU was slower on avx.
If you are referring to your Ryzen 3600, it will probably be faster with the fma version. That is what both my Ryzen 2600s end up with, though they are on Ubuntu.
PS - The difference is very small anyway, almost not worth the selection process.
Reply
Quote
If you show me an example that a Ryzen 3000's advantage is less than 3% for using avx/fma over sse2, I will be quiet on this topic forever. My guess was that it would be much more and that is why I wanted to mention the missing options for the users.
Reply
Quote