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Message boards : Graphics cards (GPUs) : Ressource-sharing between CPU and GPU projects

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bur
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Message 5281 - Posted: 4 Jan 2009 | 23:11:20 UTC

I'm running some projects already but those only use the CPU. So I thought I could add another project that also utilizes the GPU.

But does BOINC understand that this project only (or mostly) uses the CPU? Otherwise it might happen that while GPUgrid runs, other projects get suspended resulting in one core not being fully used.

For example I have CPDN running on one core all the time and the other is shared between two other projects. If I add GPUgrid, will it run in addition to the other projects or take turns?

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Message 5283 - Posted: 4 Jan 2009 | 23:18:46 UTC - in response to Message 5281.


I have a dual-core with GPU. It runs GPUGrid on the GPU, POEM and SHA on the two cores.

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Message 5287 - Posted: 5 Jan 2009 | 1:51:35 UTC

Given that GPUGrid is does not use a whole CPU for itself, you can run two CPU-bound projects in addition to GPUGrid. What you should expect to see is that one CPU project will retain 50% of the processors on a dual core, with GPUGrid using about 30-40% (based on 6.55 application WU's), with the other CPU project getting 10-20%. Some people experience less CPU usage on Windows (Linux has much better management of the CPU load and CPU usage < 5%), but my quad core uses about 15-20% of the total processors for each GPUGrid WU -- which is where my 30-40% estimate comes from for a dual core.

So, you will see a slight reduction in the throughput of credit from one of your CPU-bound projects, but the offset is that GPUGrid gives much higher credit / work done (time). This is referred to as 2+1 (2 cpu + 1 gpu bound project running), as you will see throughout the message boards.

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Message 5294 - Posted: 5 Jan 2009 | 4:32:40 UTC

A later version of the application on WIndows 6.56 reduced the load on the CPU. It was pulled for other problems but should be back when those problems are resolved as an even later version number and you will see more done on the one CPU core ...

In other words, there are better days ahead.

There are other issues discussed in great length in other threads ... but happy use of the GPU ... :)

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Message 5312 - Posted: 5 Jan 2009 | 19:40:01 UTC

Okay, thanks. I just wasn't sure if BOINC would notice that one core isn't fully used and then let three projects run simultaneously.

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Message 5314 - Posted: 5 Jan 2009 | 19:55:19 UTC - in response to Message 5312.

Okay, thanks. I just wasn't sure if BOINC would notice that one core isn't fully used and then let three projects run simultaneously.


On my i7 with 8 virtual CPUs (4 cores with HT ... total 8 apparent CPUs) the computer is running 9 tasks ... one on the GPU "stealing" some time from one of the cores (or all of them in round robin of some sorts) while on my 4 core Q9300 I have 6 tasks running, 4 on the cores, one Non-CPU intensive (FreeHAL which beats the heck out of the network, but uses very little CPU) and the one task on the GPU which also steals from the CPUs ...

But this is with Version 6.5.0 of the BOINC Manager, my understanding is that with the earlier versions you have to fiddle around with an external file to get the full usages ...

Regardless, there are still issues with work fetch, resource share, and the server here ... though some of us have had random luck the last 24 hours so I am not sure if they changed something and just have not told anyone, or if it is just because it is Wednesday ...

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Message boards : Graphics cards (GPUs) : Ressource-sharing between CPU and GPU projects

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