Re: [exim] HArdware Suggestions for exim courier-imap

On Tue, 2005-08-16 at 07:46 -0700, Marc Perkel wrote:
> A few quick thought. You can never have too much ram. As to raid, I'd
> just use Raid 1 - it's faster than raid 5. If you're running Linux I
> like the reiser file system for email because it has unlimited inodes.
> As to CPU - if you are running spam filtering especially spamassassin
> the good fast processing helps. If you want to save money I think the
> new dual core Athlons from AMD would be very cost effective.

RAID 1 is faster if you don't have the CPU. But with a hardware RAID
card, or basically any CPU made in the last five years, you should have
enough power to perform the xor calculations needed to distribute the
parity blocks. The RAID 1 is faster with reads, as they can be spread
across the drives. But when writing to a RAID 1 array all data must hit
all drives, so you are only as fast as the slowest drive in the array
(most people just use two or three of the same drive, but still you are
limited to the speed of that drive). With RAID 5 reads and writes are
distributed across multiple drives. The more drives in the array the
better the performance (up to the speed of the bus). There is an
additional overhead of the parity data but it is minimal.

--
Chris