@anvil- you're correct, sorry (always thinking a generation ahead) but I meant the 510/elmcrest not the 520/cherryville. Problem with the 3xx is that they're all 3Gbps, not a problem in itself (as I don't except a single drive to do more than 100MB/s) but I'm looking to put them all into external chassis so want to make sure that all are running at 6gbps for the expander(s). (I've run into problems before mixing/matching, it's better to have everything the same signaling).

@Ao1, yes, that's what I thought as well. I was actually planning on 28% or so over-provisioning for whatever SSD. Just trying to pick the right ones for the workload. Since this is a 'write cache' drive (it's main purpose is to cache all random writes to the back-end datastore which is ~200TB) with about 100GB/day I don't want to have the replacement issues at work (don't know the actual brand, but EMC&Oracle use SSD's for their Tier 0 in the sans, for heavy database functions they don't last a year. Not a big deal as the client's are paying for the speed so the thousands $$/drive is not an issue. A 'little' different for a home system however.