Might want to check some numbers
Interesting article but for one minor discrepency.
Each RamSan400 is capable of 400,000 IOPS by itself, in a similar sized array the number of IOPS available would be much higer than 1,000,000. For 4 TB we would actually recommend the RamSan440 for its larger capacity and 600,000 IOPS. At 4 TB that would be eight of the RamSan440's with a capacity of 4,800,000 IOPS and latencies of less than 50 microseconds (15 microseconds at the FC interface). Unlike the FusionIO card, these IOPS come at no penalty to the host CPU, in fact the host usually ends up with more usable CPU cycles per second since fewer are spent waiting on IO.
Of course the RamSan-500 is capable of 100,000 IOPS (more if most are cache hits) and provides 2 TB of capacity with an additional 64 GB of DDR cache with up to a 15 microsecond latency to the FC interface best case and 200 microsecond latency worst case. Putting two 500s together for a 4 TB array would yield at least 200,000 IOPS.
Otherwise, nice article!