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Message boards : Multicore CPUs : use more cpu

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Mitchell
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Message 751 - Posted: 13 Jan 2008 | 23:00:34 UTC

When I watch ps3 grid procs running, it never goes beyond 10% use, how can I force it to use more? My options in boinc already allow for up to 100% usage, it just doesnt use it.

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Message 752 - Posted: 14 Jan 2008 | 0:34:10 UTC - in response to Message 751.

When I watch ps3 grid procs running, it never goes beyond 10% use, how can I force it to use more? My options in boinc already allow for up to 100% usage, it just doesnt use it.

What you see is only the usage of the main PowerPC CPU. BOINC is not set up to measure the use of the 6 SPE Cells available on the PS3, which are used all by the application and run at maximum. So you could say you are running at 610%, in reality the work done by one PS3 is equal to approximately 16 single core CPU\'s of the same speed. There is no additional use that will speed along the results of the SPE\'s so running the PowerPC CPU at 100% would just be a waste of energy and heat. In simple terms it is kind of like this, think of it as the PowerPC does the disk or memory reading/writing and passes data and instructions to process the data to each of the 6 SPE\'s, it has to wait for one of them to finish, then it gets the result and passes more to that SPE, they need not all finish at the same time. Each SPE can be running different parts of the problem, kind of like attacking it from 6 sides, instead of just starting at the beginning. It operates entirely differently from all other CPU\'s we are use to.

Mitchell
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Message 753 - Posted: 14 Jan 2008 | 2:19:41 UTC - in response to Message 752.

Thanks for the explanation. I was wondering what was going on. I guess its common for ps3grid boinc runs to go for about 30-35 hours then? What kinda of credit return can be expected for such a run?

When I watch ps3 grid procs running, it never goes beyond 10% use, how can I force it to use more? My options in boinc already allow for up to 100% usage, it just doesnt use it.

What you see is only the usage of the main PowerPC CPU. BOINC is not set up to measure the use of the 6 SPE Cells available on the PS3, which are used all by the application and run at maximum. So you could say you are running at 610%, in reality the work done by one PS3 is equal to approximately 16 single core CPU\'s of the same speed. There is no additional use that will speed along the results of the SPE\'s so running the PowerPC CPU at 100% would just be a waste of energy and heat. In simple terms it is kind of like this, think of it as the PowerPC does the disk or memory reading/writing and passes data and instructions to process the data to each of the 6 SPE\'s, it has to wait for one of them to finish, then it gets the result and passes more to that SPE, they need not all finish at the same time. Each SPE can be running different parts of the problem, kind of like attacking it from 6 sides, instead of just starting at the beginning. It operates entirely differently from all other CPU\'s we are use to.

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Message 754 - Posted: 14 Jan 2008 | 5:22:50 UTC - in response to Message 753.

Thanks for the explanation. I was wondering what was going on. I guess its common for ps3grid boinc runs to go for about 30-35 hours then? What kinda of credit return can be expected for such a run?


A typical Workunit will last between 24-27 hours and you can expect around 3,700 credits

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Message boards : Multicore CPUs : use more cpu

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