GPUGRID: improved performance via SWAN_SYNC=0

[zombie67]

Check out this thread:

http://www.gpugrid.net/forum_thread.php?id=2327

Reading through it, and other other threads there, there is significance performance improvement to be gained by using the "SWAN_SYNC=0" environmental setting. It dedicates a thread to the GPU. Anyone tried this?

[-GER-]

Check out this thread:

http://www.gpugrid.net/forum_thread.php?id=2327

Reading through it, and other other threads there, there is significance performance improvement to be gained by using the "SWAN_SYNC=0" environmental setting. It dedicates a thread to the GPU. Anyone tried this?

I did the other day and it definitely made a diffence. Gpu usage went from about 60% to 74%. The longer 8-12 hours wu's pay considerably better too. I have also read that you get a credit bonus for returning wu's promptly dunno about that.

[zombie67]

I have also read that you get a credit bonus for returning wu's promptly dunno about that.

This is true. So when you crunch GPUGRID, you should keep a very small cache. Something like .5 days or less. That way it does not download the 2nd task until the 1st one is almost done.

[Maxwell]

So I can find the instructions again...


This is good. If you want maximum performance, you should dedicate one CPU core to feed the GPU. Use the SWAN_SYNC=0 environmental setting to achieve this. (control panel -> system -> advanced tab -> environment variables -> new (system variables) -> variable name: SWAN_SYNC value: 0 -> restart windows)

[Dorsilfin]

I tried this out.. My performance went from 70% to around 40%... however when I pause all my CPU tasks I shoot up to about 88%.

Is there a way to leave 2 cpu's open to feed my 2 gpu's while still churning cpu work units?

[DAD]

Yeah lower boincs CPU use by the "On Multi Processors Use XX%" option

Since I have an "8 core" system, every 12.5% = 1 CPU

on 4 cores, it's 25% per cpu

So if you want 2 CPUs free for 2 GPU tasks on a 4 core system, set the value to 50% (75% for an 8 core would leave 2 free)

[DAD]

I just added the swan_sync 0 variable to My i7-2600K machine and rebooted it.. the GPUGrid forums are very wrong that this is only for a 400 line or linux systems..

With these 560TIs, I was doing 600-800Mflops/sec on long runs, once I set swan sync to 0, I'm doing 4.2GFlops/sec on GpuGrid "long runs" however, I can't let boinc use more than 75% (6 cores) or my performance goes to hell

I don't recommend doing this on a dual core machine with 2 GPUs unless you want to crunch GPU only tasks.

So for me this is over a 500% increase in speed with this setting for my GPU WUs! :)

[Dorsilfin]

Yeah lower boincs CPU use by the "On Multi Processors Use XX%" option

Since I have an "8 core" system, every 12.5% = 1 CPU

on 4 cores, it's 25% per cpu

So if you want 2 CPUs free for 2 GPU tasks on a 4 core system, set the value to 50% (75% for an 8 core would leave 2 free)


Wouldn't this just take 2 cores away from BOINC?

or is it only 2 cores away from tasks within boinc.. and the 2 spare cpu's will feed still?

[DAD]

Wouldn't this just take 2 cores away from BOINC?

or is it only 2 cores away from tasks within boinc.. and the 2 spare cpu's will feed still?

Well you can't specify cores... so on a 4 core, 50% takes 50% load of the 4 cores so "2 cores" of power are left. 75% for an 8 core.

If you do the swan sync and leave the setting at 100% then your GPU and CPU tasks will all suffer as there won't be enough CPU time available.