PATCH: Altivec support for RAID-6

H. Peter Anvin hpa at
Sun Oct 31 10:37:59 EST 2004

This patch allows the RAID-6 code to use Altivec on ppc/ppc64 
processors.  Note that it uses gcc <altivec.h> support, so it might 
require a fairly recent gcc -- but I haven't been able to get a clear 
answer on *how* new.

It also changes -mcpu=power4 to -mcpu=970 when CONFIG_ALTIVEC is 
enabled, since -mcpu=power4 doesn't allow -maltivec to be specified with 
it :(

The results are *impressive*, however; on a PowerMac G5 I get 6.1 GB/s 
(on one CPU!); this is close to the 7.8 GB/s for RAID-5, and almost 2x 
what my 3 GHz Pentium4 gets.


Signed-Off-By: H. Peter Anvin <hpa at>
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