[mythtv-users] Wishlist feature for adding a hard drive

[Stephen Boddy]

On Thursday 05 October 2006 19:20, Robert Kulagowski wrote:
> > If you're using software RAID (md) then your writes will take a hit with
> > RAID5.
>
> Isn't XOR one of the most optimized routines in a CPU?  I recall reading
> a paper put out by Microsoft a few years ago where they benchmarked
> software RAID versus hardware RAID, and that software RAID wasn't as bad
> as everyone thought it should be precisely because a modern CPU can
> execute XOR so quickly.

While that may be true, the main point I'm getting at is that RAID5 won't 
improve write speeds, because instead of a single write to a single disk, 
there are at least two reads, a calculation (however short), followed by two 
writes. (Obviously this is ignoring caches/buffers etc.)

-- 
Steve Boddy