PGI User Forum
 SearchSearch   MemberlistMemberlist     RegisterRegister   ProfileProfile    Log inLog in 

Free OpenACC Webinar

max memory with pinned data

 
Post new topic   Reply to topic    PGI User Forum Forum Index -> Accelerator Programming
View previous topic :: View next topic  
Author Message
Tuan



Joined: 11 Jun 2009
Posts: 233

PostPosted: Fri Feb 12, 2010 7:13 am    Post subject: max memory with pinned data Reply with quote

Hi,
Could someone tell me how PGI Fortran define the maximum available memory for pinned host data.


Tuan
Back to top
View user's profile
mkcolg



Joined: 30 Jun 2004
Posts: 6208
Location: The Portland Group Inc.

PostPosted: Fri Feb 12, 2010 1:00 pm    Post subject: Reply with quote

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
Back to top
View user's profile
Tuan



Joined: 11 Jun 2009
Posts: 233

PostPosted: Fri Feb 12, 2010 6:50 pm    Post subject: Reply with quote

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.
Back to top
View user's profile
mkcolg



Joined: 30 Jun 2004
Posts: 6208
Location: The Portland Group Inc.

PostPosted: Sat Feb 13, 2010 1:11 pm    Post subject: Reply with quote

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
Back to top
View user's profile
Tuan



Joined: 11 Jun 2009
Posts: 233

PostPosted: Mon Feb 15, 2010 7:59 am    Post subject: Reply with quote

Gotcha,
Tuan
Back to top
View user's profile
Display posts from previous:   
Post new topic   Reply to topic    PGI User Forum Forum Index -> Accelerator Programming All times are GMT - 7 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © phpBB Group