Working with the hardware I already have, I'm trying to optimize the last mile here. I have a 9265-8i with BBU and CC Pro 2.0. I have 4 7200RPM Seagate ES.3 drives running in a RAID 10. Running 4 to 5 mixed use Virtual Machines serving a small group of 10 people. Just typical MS stuff going on like Exchange, File Serving, Domain Controller, Quickbooks. Very light daily use.
The last mile I'm looking to fill is the SSDs for my CacheCade. In hindsight, I might have spent the money differently on S3700s, but it is what it is and I have to work with it unless I dump it all on ebay and that's just not going to happen.
I have 4 520s which I could easily use for the CC, but I have another idea for them on a VDI box. So I have about 1100$ to spend and am looking at the S3500, 4x240GB in a Raid 10 for the CC. The reviews on the S3500 are sold, I have 2 120G S3500 and they outperform 2 520s in the same config on the random 4K read and equal the 520 on the random 4k write.
So my only concern is the write speeds, which are half of the read speeds on the 240G on paper. Do VMs read more than write? (terrible question)
In a RAID 10, I should get solid Read and respectable Write (maybe even better than the 520s from what I see in random 4k). For the same money, I could go with the Intel 530s, but believe the S3500 will perform better under loads and over the long haul.
Raid10 for CC is a waste and - to be honest - I wasn't aware raid10 was supported for CC. The SSD is fast enough on it's own striping won't speed things up even if it's available.
Run 2 drives in Raid1 [so you can safely use write-cache] and go with the 3700's over the 3500's imho but the 520's should work fine as well I believe they're on the tested/approved list [verify this yourself].