snef

scatter/gather array:  how to copy to/from graphical memor

Discussion created by snef on Nov 9, 2009
Latest reply on Nov 10, 2009 by youplaboom

If you creat a stream (for input) you have to perform a read to fill it up. The read will copy from main (=host) memory over the PCIe to the graphical memory.

How ever if you creat a scatter/gatther array as in float4 ar[1024] and fill it up in main memory. How do you create that array in graphical memory and how do you copy it?

I think that you can just use that array in the kernel call and  brook+ will under the hood do the copy.

What happens if you first use a gather/scatter array as output for kernel1 and then use that array as input for kernel2. Is there a copy to main memory performed?

Where/how do you declare that array: I do't need it in main memory.

 

Any help appreciated.

 

Sven

 

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