What is good settings for my ATI R5770?

[KarVi]

Has anybody done some testing into what "-unroll -ffa_block -ffa_block_fetch -sbs" settings works most efficiently for a Radeon 5770?

Defaults seems to be "-unroll 4 -ffa_block 2048 -ffa_block_fetch 1024 -sbs 128", when you use the installer, but must also be based upon less powerfull cards and their abilitys.

[Mike]

-unroll 10 -ffa_block 6144 -ffa_block_fetch 1536 should work fine.

Sbs switch not needed atm.

[KarVi]

Thanks.

Also got basically the same settings fra Claggy, but had problem getting it to run.

Just got short bursts of 30% usage on GPU, and slow progress in crunching.

But one more restart of boinc seems to have cured it, now crunching with 75-99% GPU usage, and it seems to be faster than with standard settings.

I hope it lasts, time will tell

[Claggy]

Thanks.

Also got basically the same settings fra Claggy, but had problem getting it to run.

Just got short bursts of 30% usage on GPU, and slow progress in crunching.

But one more restart of boinc seems to have cured it, now crunching with 75-99% GPU usage, and it seems to be faster than with standard settings.

I hope it lasts, time will tell

That will be the GPU usage Bug a fair amount of us are suffering from, suspending GPU usage, waiting for the app to exit (watch task manager), then resuming often gets high GPU usage again,

Claggy

[Mike]

Donīt forget GPU usage also differs on high blanking.

[Raistmer]

Yes, if GPU processing few heavely blanked tasks there can be GPU usage drop even with few tasks per card.
But I think there is the way to distinguish such pattern from GPU low usage bug pattern.

Heavely blanked pattern should have almost 100% spikes when FFA done on GPU (it's best optimized partion IMHO cause I worked on it from Brook+ times). Blanking affects on processing between FFAs and FFA itself should make use of almost all GPU.
Whereas low usage bug pattern will shouw steady low % perhaps.

Not sure in that but you can make observations and improve my suggestion.

[Mike]

Did that already.

On AP using r558 GPU usage bouncing between 20% and 45% running 2 instances.
On high blanking its bouncing as well so you only can try with suspend and resume.

My times varies between 3000 secs and 10000 secs with blanking less than 15%.

Additional note:

While on MBs suspending work cures at least for whole unit in progress, on APs low GPU load returns after a few minutes sometimes.
I imagine it depends on steadily CPU usage ?

[Raistmer]

WoW, good observation!
No, I think not.

There is key difference in buffer allocations for MB and AP.
While MB does more or less homogenic calculations AP implements 2 almost independent sections - main loop and FFA.
For FFA we need different buffers (different number, different sizes) than for main loop single pulse search.
Hence there is only once buffers allocation in MB, at the beginning, but constant buffers recreation/discarding for AP.
Before there was opinion that low GPU usage bug can be connected with orphaned OpenCL resources left behind when task finished. Indeed, I did not directly deallocate buffers in MB leaving cleanup for OS/OpenCL runtime (as should be when OS process get killed).
But I do buffers deallocation in AstroPulse ! When transition from main loop to FFA occurs some of main loop buffers are deallocated and FFA ones are allocated, and vice versa. So, the problem not in deallocation, the problem in allocation!

No clue how to fix it on our end still, but at least it's good bug report to AMD.

[Claggy]

This is the sort of load i get with ATI AP when there is minimal load:



and this is what it like once i've suspended and resumed the Wu (notice the higher frequency of memory usage):



Claggy

[KarVi]

That is exactly what it looks like on mine as well.

I must note that I hadn't noticed the error before optimizing the settings.

I'm thinking about going back to see if it disappears with the standard settings...

[Raistmer]

This is the sort of load i get with ATI AP when there is minimal load:
Claggy

How many tasks per GPU in fly on that picures ?

[Claggy]

This is the sort of load i get with ATI AP when there is minimal load:
Claggy

How many tasks per GPU in fly on that picures ?

I only ever run 1 task per GPU, it enables me to see what the app is doing, rather than having multiple apps masking the problem,

Claggy

[Raistmer]

Yes, your approach is right for app testing. Host performance suffer in such mode though.
But then your picture "kills" my method of bug/blanking discrimination.
There are spikes of bigger load (I think it's FFA) on you "low GPU bug" picture... And those spikes much less visible (though exist) in "full load" mode.

[Raistmer]

BTW, look for memory graph.
There are "spikes"  - they corresponds short FFA (most of them).
Look how often they occur on "fast"task and how wider (X-axis is time so wider =slower) they are on "slow" task.
But amount of computation between them is just the same!
Hence we have slowdown not just in some area of algorithm. Whole processing more or less equally slowed. single pulse search takes more and FFa takes more too.
It's important result cause it can decline assumption that there are just many false positives from near to threshold reesults in FFA so much more bus transfers are needed. In that case FFA would took much longer while single pulse (main loop) - not. So we would see disproportional increase in max or min memory usage time.

[Claggy]

Another thing to note, when ATI AP app is suffering from low usage Bug, ATI driver restarts have occured on number of occasions,
normaly this occurs when i have been away from the computer, and i start browsing, driver restart occurs, i check SIV/GPU-Z and find there has been little ATI GPU usage,
and lots of elapsed time, and little % progress, suspending & resuming gets the app working with 80%+ GPU load,
on a couple of occasions i've come back from work and found the app a couple of hours in but with 0% done, i suspect a driver restart happened there too,
suspending/resuming has got it working.

Claggy