Re: MMX performance....

David S. Miller (davem@jenolan.rutgers.edu)
Thu, 6 Feb 1997 17:42:16 -0500


Date: Thu, 6 Feb 1997 17:26:36 -0500 (EST)
From: Robert L Krawitz <rlk@tiac.net>

What's the break-even copy size? Your patch seems to suggest 512 or 1024
bytes.

It probably depends on the memory architecture. On my system (Neptune
mobo, 90 MHz, memory clocked at X-3-3-3) it wins even at 256 bytes. I
suspect with EDO it's a bit higher, in the 512-1024 byte range.

The break even point on UltraSparcs for FPU bcopy is around 256 bytes,
for bzero it's ~128 bytes.

---------------------------------------------////
Yow! 11.26 MB/s remote host TCP bandwidth & ////
199 usec remote TCP latency over 100Mb/s ////
ethernet. Beat that! ////
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David S. Miller, davem@caip.rutgers.edu /_____________/ / // /_/ ><