On Sunday 23 March 2008 7:11:41 am Kieran Clancy wrote: [snip] > So the total cached read bandwidth seems limited to about 2250 MB/s, > which is slightly higher than the cache read bandwidth for /dev/md2, > but I'm not too worried about that. More concerning is that I am > still getting ~80MB/s from each disk simultaneously on the buffered > reads. Given this I would expect /dev/md2 to give buffered read > speeds of at least 120MB/s (if not 150MB/s). The value of RAID 1 isn't speed. it's fault tolerance. I would expect what you're seeing, a slight performance *loss* (relative to a single disk) due to the additional overhead of the RAID management. http://www.linuxhomenetworking.com/wiki/index.php/Quick_HOWTO_:_Ch26_:_Linux_Software_RAID#RAID_1