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Tuan
Joined: 11 Jun 2009
Posts: 226
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 Posted: Fri Feb 12, 2010 7:13 am Post subject: max memory with pinned data |
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Hi,
Could someone tell me how PGI Fortran define the maximum available memory for pinned host data.
Tuan |
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mkcolg
Joined: 30 Jun 2004
Posts: 4996
Location: The Portland Group Inc.
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| Posted: Fri Feb 12, 2010 1:00 pm Post subject: |
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Hi Tuan,
It depends on how much the OS has available. CUDA Fortran just makes a call to the OS to request the memory. If the request fails, then regular memory will be used.
- Mat |
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Tuan
Joined: 11 Jun 2009
Posts: 226
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| Posted: Fri Feb 12, 2010 6:50 pm Post subject: |
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| mkcolg wrote: | Hi Tuan,
It depends on how much the OS has available. CUDA Fortran just makes a call to the OS to request the memory. If the request fails, then regular memory will be used.
- Mat |
Is that limited by the physical RAM memory? As data in pinned memory is faster for data transfer to device memory than normal host data, I don't know which kind of memory will hold pinned data?
Tuan. |
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mkcolg
Joined: 30 Jun 2004
Posts: 4996
Location: The Portland Group Inc.
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| Posted: Sat Feb 13, 2010 1:11 pm Post subject: |
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Hi Tuan,
| Quote: | | Is that limited by the physical RAM memory? |
This would be the max assuming the OS is able to give you all the physical memory. Realistically it will be lower and depend upon what else is happening on your system.
| Quote: |
As data in pinned memory is faster for data transfer to device memory than normal host data, I don't know which kind of memory will hold pinned data? |
Our internal testing shows that pinned memory only helps when you can reuse it for multiple transfers. Otherwise, it doesn't help.
- Mat |
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Tuan
Joined: 11 Jun 2009
Posts: 226
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| Posted: Mon Feb 15, 2010 7:59 am Post subject: |
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Gotcha,
Tuan |
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