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xmuben
Journeyman III

questions about attribute groupsize

Attribute[groupsize(x,y,z)] in Stream_Computing_User_Guide.pdf. 

Attribute[groupsize(256,1,1,1)]:   why is it valid? Does it mean that there are 256 threads in this group? or there are 256 groups and 1*1*1 thread in each group?

Attribute[groupsize(64,2,1,1)]:    why is it  invalid?

And why do the both have four parameters?

If I want to define N groups and M threads in each group, How do I define it?

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gaurav_garg
Adept I

Attribute[groupsize(256,1,1,1)]

mentions that there are 256 threads in the group. The other 3 dimensions show number of threads in y, z and w direction.

Currently, only group of 1D size is supported, that's why the second attribute declaration is wrong. But, it can be supported in future.

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Originally posted by: gaurav.garg Attribute[groupsize(256,1,1,1)]

mentions that there are 256 threads in the group. The other 3 dimensions show number of threads in y, z and w direction.

Currently, only group of 1D size is supported, that's why the second attribute declaration is wrong. But, it can be supported in future.

 

Thank you for your answer.  I got it.  Since Brook+ doesn't work like NVidia CUDA. Here I got another question. I want to transfer my application from CUDA to Brook+, and I need a large count of global memory(may be 100M  in 1D form), while the max size of 1D array is 8192 bytes. It can't meet with memory requirement.

However, My Ati  card memory is 1024M. If I want to use the memory, How do I operate it?

 

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You can use 2D scatter stream(of size upto 8192x8192) or use Catalyst 9.2 in which address translation works and you can use 1D streams of size > 8192.

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Does Catalyst™ Version 09.5  also support this?

My brook+ version is 1.4

My ATI card is Radeon HD 4800 Serial.

Thank you again.

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No, it does not work with 9.5 or 9.6. It used to work in Catalyst 9.3, not sure if it works with 9.4.

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