Are GW work units getting longer?

alanb1951
alanb1951
Joined: 28 Nov 16
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Bill wrote: For the 2700, I

Bill wrote:

For the 2700, I have been experimenting with only using 14-15 cores for BOINC (two of those cores are supporting GPU tasks).

Something seems off, but I don't know what.  CPU is keeping very cool, and I've got a steady clock of 3.7 GHz.

Just a thought -- "CPU is cool and jobs take a long time" sounds like L3 cache is being hammered so the apps effectively become memory-bound.

I don't run Einstein CPU jobs so I've no idea as to how much L3 cache might be needed per task to avoid this;  I'd suggest limiting the number of GW tasks (and any other large-footprint tasks if you run other projects!) to see if things improve...

(I had a similar experience on WCG with their MIP1 project (based on Rosetta code) - running more than one of those per 4MB of L3 cache was a sure-fire way of slowing the machine down even though it stlll reported reasonable clock rates!)

Cheers - Al.

Ian&Steve C.
Ian&Steve C.
Joined: 19 Jan 20
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Gary Roberts wrote: The

Gary Roberts wrote:

The other factor might be the PCIe bandwidth demands of 11 rosetta tasks.

Rosetta being a CPU-only project, has nothing to do with PCIe bandwidth.

If you watch PCIe bus use while crunching Einstein, it's very low anyway, 0-1%. PCIe bandwidth is not a factor here. It's a CPU/memory bottleneck.

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Tom M
Tom M
Joined: 2 Feb 06
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Bill wrote: This may not be

Bill wrote:

This may not be exactly related, but I'm having similar concerns about the GW CPU tasks.

 

I just upgraded to a 2700 (non-X), and the GW 2.09 CPU tasks are taking about a day to complete on Windows 10.  I'm running E@H on a really old laptop, and those tasks are taking about 7 hours...but they are using the GW 2.08 application.

I have discovered that GW CPU tasks appear to be taking 3 CPU threads.  On an AMD 3950x (16c/32t) if I run more than 10 GW CPU tasks they slow down considerably.  Right now they run 4-6 hours.  If I run 26 tasks they slow to more than 12 hours.

I had to upgrade my ram to 64 GB to discover this.

Tom M

Missing Tag.....         where? where?

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