John R Pierce wrote:
Chan Chung Hang Christopher wrote:
I've read a lot of different reports that suggest at this point in time, kernel software raid is in most cases better than controller raid.
Let me define 'most cases' for you. Linux software raid can perform better or the same if you are using raid0/raid1/raid1+0 arrays. If you are using raid5/6 arrays, the most disks are involved, the better hardware raid (those with sufficient processing power and cache - a long time ago software raid 5 beat the pants of hardware raid cards based on Intel i960 chips) will perform.
not if you're doing committed random writes such as a transactional database server... this is where a 'true' hardware raid controller with significant battery backed write cache will blow the doors off your software raid.
See my reply to nate. If you are using boards with 12GB of cache, software raid is not even on the radar.