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Marco Costalba
8d369600ec
After fixing the cpu frequency with RightMark tool I was able to test speed all the different prefetch combinations. Here the results: OS Windows Vista 32bit, MSVC compile CPU Intecl Core 2 Duo T5220 1.55 GHz bench on depth 12, 1 thread, 26552844 nodes searched results in nodes/sec no-prefetch 402486, 402005, 402767, 401439, 403060 single prefetch (aligned 64) 410145, 409159, 408078, 410443, 409652 double prefetch (aligned 64) 0+32 414739, 411238, 413937, 414641, 413834 double prefetch (aligned 64) 0+64 413537, 414337, 413537, 414842, 414240 And now also some crazy stuff: single prefetch (aligned 128) 410145, 407395, 406230, 410050, 409949 double prefetch (aligned 64) 0+0 409753, 410044, 409456 single prefetch (aligned 64) +32 408379, 408272, 406809 single prefetch (aligned 64) +64 408279, 409059, 407395 So it seems the best is a double prefetch at the addres + 32 or +64, I will choose the second one because it seems more natural to me. It is still a mystery why it doesn't work under Linux :-( Signed-off-by: Marco Costalba <mcostalba@gmail.com>