Very low GPU usage on iMac
![[AF>Le_Pommier] Jerome_C2005](https://einsteinathome.org/sites/default/files/imagefield_default_images/default-avatar.png?1347855344 "[AF>Le_Pommier] Jerome_C2005"){kind=avatar}
14 Jul 2021 10:39:34 UTC
Topic 225690
(moderation:
Hi All
It's been a long time I don't help on Einstein so I decided to give it a go, GPU only (I dedicate CPU to other projects), I switched yesterday afternoon from milkyway to einstein_O3AS / GW-opencl-ati.
I just realize that almost no GPU is used by the application !
and in CPU it is using an average 25/30% of one thread.
What does it mean ? is this a macOS issue ? or my GPU in particular ? (Radeon pro 5700 XT)
I just decided to try to run 4 in parallel (using app_config, that's why it has 4 rows in my screenshot but it's not the GPU history starting yesterday 15:00), I will see the behavior.
Thanks for your feedback.
After several hours with 4
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After several hours with 4 tasks it's almost the same, GPU is hardly used. It seems this application is not "compatible" with my GPU.
I cancelled all these tasks and removed this app from my preferences, I'm now crunching Gamma-ray pulsar binary search #1 on GPUs / FGRPopencl-ati-mav and now it's working much much better, GPU is well used ! almost 75% usage, sometimes less, I'm now trying with 2 tasks in parallel.
{AF>Le_Pommier} Jerome_C2005
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The O3AS1 search is quite new and is the first search using the O3 data from the LIGO detectors. It replaces the the O3ASE engineering test run which was using fake data to test out the new app.
There is an existing thread which was started just as the first real data started to be issued. The 'beta test' part of the thread title is misleading since there was no formal announcement of the start of the real data and consequently the thread starter couldn't have known that this was no longer a test. I wish one of the staff would reinstate the practice of having formal announcements that actually precede major changes like this.!!!! :-). A bit of forewarning would really be appreciated by those volunteers who get clobbered by sudden unannounced changes!!
If you look at the results for some of those participating in that thread, you can see that run times are much shorter than what you have experienced. As an example, here is a recent workunit that just happens to be shared by the first two participants in that thread. One computer has a 1660Ti GPU whilst the other has an RX 5600. Both of these are probably (just a guess) inferior to your GPU but both have run times extremely shorter than yours - 1600s and 1150s respectively.
My guess is that something in the Apple system is not allowing your GPU to function normally. I don't have any knowledge of what that might be.
Cheers,
Gary.
[AF>Le_Pommier wrote:
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I also have a 1660Ti running under Windows on a laptop and they seem to work fine for me, so barring it being an actual Apple problem...try running 1 task at a time on that AMD 5700XT of yours and see what happens then. 2nd try suspending all cpu tasks and see if the crunching speeds up as during testing we discovered there is ALOT of cpu time needed for these tasks and if you are doing the standard 0.25 cpu core usage settings while running 4 tasks at a time you could be starving the gpu or making it share too often with your cpu tasks.
As you can see on my 1st post
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As you can see on my 1st post I've been running during one day just with one task, my first screenshot is taken before I tried with 4 tasks : almost no GPU used and few CPU per task (25%).
Before this the "almost 100%" you can see to the left of my 1st screenshot was achieved with 2 milkyway tasks (1 was not enough) : no problem
After this, since I switched to FGRPopencl-ati-mav (instead of O3AS1) : no problem
I'm now running 2 FGRP in parallel because GPU was not full enough for me, the GPU usage is now looking like this :
Not 100% but much better !
So yes, the issue is O3AS1 OpenCL on a Mac + my particular GPU also probably.
I'm sorry to here it's a mac
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I'm sorry to here it's a mac and your gpu problem, I have a much older mac and will put a gpu in it in a couple of weeks, not nearly as good as yours, and will hope for better results.