Adaptec RAID 51245 2268100-R SATA/SAS 16-port (12 internal,4 external) w/ 512MB cache memory Controller Card, Single

Pros: Blazingly fast...with a 500GB dd dump I'm getting 868 MB/s writes and 1000 MB/s reads, with an hdparm score of 865 MB/s on a 12-drive RAID 6. This is right in line with my other 51245 on a similar setup (see "Other thoughts" below). Speaking of the other setup, it's been going strong for over a year now without issue.

Cons: None

Other Thoughts: Me again...bought a second 51245 for use in the same machine alongside the first one, this time with 12 Hitachi H3D40006472SE 4TB 7200 RPM drives in RAID 6 on XFS (this machine now has two 12-drive RAID 6 arrays, powered by two Adaptec 51245, for 70TB total storage).

Pros: It's very fast (especially compared to equivalent 3ware cards), stable, and the drivers are built into the Linux kernel, no more custom compiling the driver every time you update your kernel like with other manufacturers.

Cons: None

Other Thoughts: I've been a long time 3ware user, and finally decided to make the switch. The improvements are drastic, with no negatives that I've seen. This card has been running a 12-drive 30TB RAID6 24/7 since June '11 (7 months ago) with phenomenal performance and not so much as a hiccup. The array is currently about half full.

With 12 Hitachi H3IK30003272SW 3TB drives in RAID6 using XFS, I'm getting 871 MB/s writes and 894 MB/s reads using dd dumps, and an hdparm score of 963 MB/s. Not bad for a $3k 30TB double-parity array! Based on my extensive experience with 3ware, one of their equivalent cards might match the read speed, but the writes would only hit 1/3 to 1/2 of this, if you were lucky.