Very useful information for those down the path of SSD caching. I'll offer my setup as food for thought for those of you thinking this through.
First off, an SSD cache can only cache 1 volume. This volume can be partitioned like any hard disk, i.e. C, D, E, etc, but the cache can only cache a single volume.
This is an important fact because what if your OS is on the C, and let's say it's a mirror, and then you have a raid0 for games etc... you can't cache them both because in this scenario they are two volumes. Another scenario using IRST is multi volume configuration on a raid set, raid 1, 5, 10, etc. You can't boot to larger than a 2TB volume using MBR so if you make a <=2TB MBR and the rest a GPT, guess what? It's 2 volumes and you can't cache them both!
I solved this issue by UEFI booting to a RAID10 array. I use 4 x 2TB 3gb/sec Seagate Constellation Enterprise SATA drives. This created a single 3.6TB volume which I partitioned C to 500gb and D to 3.1TB. I use a OCZ Vertex4 64gb SSD to cache the entire "volume" (partitioned in this example to C & D), and I get the performance and redundancy of a RAID10 array boosted by SSD caching. As a note: I do not set the cache to maximized, rather optimized mode, because my rig is not a pure gaming rig, and I burned myself once with lots of cross linked files "tinkering" while the cache was set to maximized.
Why 3gb/sec vs 6gb/sec SATA? because Intel only provides 2 6gb/sec ports on most motherboards, and one of those should be your SSD cache drive. I've never seen a motherboard with 4 6gb/sec ports on the Intel controller, only 2 on the Intel and 2-4 on the secondary controller. Also, the Intel controller servicing a RAID10 array on the SATA 3gb/sec ports offers optimized raid set performance. I believe it'll be bottle necked by the drives, not the controller. So I suggest there is no need for a raid10 6gb/sec disk set on Intel desktop raid controllers to date until drive performance gets significantly better, but what do I know
You could of course do the same thing on a raid0 or raid5 with 4 disks configuration, I just use raid10 for redundancy and performance characteristics.
For your information, a pic of my IRST setup, and ATTO benchmark. The cache was warmed up for this benchmark so you see enhanced read performance, when not warmed up the read and writes were about the same performance, and If I was using maximized mode you'd see better write performance.
Happy Caching Edited by Undermoose - 3/12/13 at 7:57pm