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.