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Altera_Forum's avatar
Altera_Forum
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8 years ago

get_global_id(0) cause much latency ?

Hi I'm trying to compare the performance of FPGA and GPU based on image processing algorithm. I've found that there's a 10ms different when using the get_global_id(0) and not using it. The kernel ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
8 years ago

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I'm confused. "begin" as the work-item number is not used anywhere in the code. Is that a typo? Should it be:

int iIndx = get_global_id(0);

replacing the for loop?

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yes originally it was like that. I was trying to figure out what was causing all the trouble and change back to single for loop, that's why it looks like typo.

I experimented more (each modify takes one hour to compile...) and get rid off get_global_id(0) and it sill have that latency...

Let me do more test and figure what the hell is going on...