Comparison with IBM's TPC setup
It would be interesting to compare this with the set-up that IBM put together for their class-leading TPC'C' benchmark at 6,085,166 transactions per minute or about 100K per second. Most of the cost of that benchmark was in the storage listing at about $20m. It had no less than 68 disk controllers with 11,000 disk drive (8 x 146GB and the rest all 73.4GB 15K). You might, in theory, get something over 2 million random IOPs out of that many disks (before RAID overheads), but I suspect that will be at the expense of about a quarter of a megawatt of power and maybe 20 racks or more of space. Of course you would get nowhere near that 2 million random IOPs when measured at the front end due to the need to keep I/O queues down to a tolerable level and the write overhead.
Note that TPC rules allow for the vendors to discount the prices provided they would be available at that price at those volumes to real customers.
With the SSD it looks like you could hit 2m IOPs (at a much lower latency than the physical disks) with a list price of about something less than $9m in a couple of racks and what I assume is a fraction of the power requirement.
The one real downside is the amount of storage. Most of the IBM TPC'C setup was configured as RAID0 (log files, which are written serially, were RAID5). Configured as RAID0, the 11,000 mostly 73.4GB 15K drives would have offered about 400TB of storage space, so in terms of IOPs, cost per TB, power usage and (I assume) latency the SSD configuration would already be ahead. Of course those of us in "real" data centres aren't generally allowed the luxury of populating arrays with 73GB drives just to get the IOPs up - 300GB 15Ks (or worse) are the order of the day, so SSD falls way behind on a cost per GB basis. However, the fact that RAID-protected SSD can be a comparable in cost per GB to RAID0 protected 73GB 15K drives is very interesting.
It must be about time that a vendor does a TPC'C' run using SSDs. It's interesting that nobody seems to have yet done this, but if these numbers are correct, the nail must firmly be in the coffin of 73GB 15K enterprise drives. Cost these configurations over 5 years, including environmentals, and it is no contest. Enterprise 15K drives of about 300GB will be around for a while, but there days are surely numbered.