On Fri, Oct 24, 2003 at 06:26:55PM +0200, Ionut Georgescu wrote: > Yes, it is a 1.5MB cache CPU. > > But it might be more than just cache misses. When running with a 256x256 > grid, I am actually using 3 256x257 matrices, which is slightly over > 1.5MB. I just made a comparison with a 32x32 grid and the difference is > the same: alpha 10.294s, zx2000 14.777s . -O3 is only by 0.4s faster > than -O2 in this case. > > The variations are within +-0.02s between runs (for the 32x32 case). > > Is there a way to test the bandwidth of the cache ? Because I think the > alphas have actually 2MB of L2 cache, not L3. I don't know about testing cache bandwidth, but /proc/pal/cpu0/cache_info gives various stats on how the different levels of cache play together on ia64. -- "It's not Hollywood. War is real, war is primarily not about defeat or victory, it is about death. I've seen thousands and thousands of dead bodies. Do you think I want to have an academic debate on this subject?" -- Robert Fisk - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.htmlReceived on Fri Oct 24 12:55:24 2003
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