global vs. local memory

Discussion created by blelump on Mar 5, 2010
Latest reply on Mar 5, 2010 by MicahVillmow
some clarification would be appreciated


I'm wondering what's the main difference between such types of memory.

There are some examples for CL, which could clarify it a bit [but they don't, for me anyway] - for instance transpose or multiply matrices uses local memory and on the other hand sobel filter or matrix convolution works without any local memory.

I know that fetch data from local is probably faster than from global, but copying data from global to local also costs some time - isn't it ?

So far I assume that local memory might be more efficient while user must deal with a lot of data whereas global memory is more effective when user operates just on each element and moreover needs additional access to the element neighbourhood - Am I right ?

Thanks in advance for any response.