RE: RAID question

Bene, Martin (Martin.Bene@KPNQwest.com)
Wed, 7 Nov 2001 16:22:28 +0100


Hi Roy,

> raid5: measuring checksumming speed
> 8regs : 1480.800 MB/sec
> 32regs : 711.200 MB/sec
> pIII_sse : 1570.400 MB/sec
> pII_mmx : 1787.200 MB/sec
> p5_mmx : 1904.000 MB/sec
> raid5: using function: pIII_sse (1570.400 MB/sec)
>
> Why is raid5 using function pIII_sse when p5_MMX is way faster?

The sse version is prefered over the others and gets used regardless of
speed if it's available:

/* We force the use of the SSE xor block because it can write around L2.
We may also be able to load into the L1 only depending on how the cpu
deals with a load to a line that is being prefetched. */

Bye, Martin
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