Where Are Those eXFlash SSDs For Power Systems-IBM i?

November 28, 2011 Timothy Prickett Morgan

You only see what you are looking at, and like the rest of you in IBM i Land, I have paid close attention to the flash-based solid state drives in 3.5-inch and 2.5-inch form factors that Big Blue has offered specifically for the Power Systems lineup. But IBM’s System x and BladeCenter blade servers have even smaller and less costly SSDs that, at least according to the IBM literature, are perfectly fine for I/O intensive database workloads and that are not available on the Power Systems machines.

A recent deal for System x customers brought these smaller SATA drives to my attention. Under that deal, IBM is giving price breaks on the feature 5428 (part number 43W7726) 50 GB SSD and on the feature 5420 (part number 43W7746) 200 GB SSD, both of which are 1.8-inch units that are perfect for small systems like the very popular Power 720 that comprises most of IBM i system sales these days. These 1.8-inch SSDs are also known as eXFlash, just so you don’t get confused. Here’s the marketing pitch for them:

IBM’s sales pitch for 1.8-inch SSDs for System x machines. (Click graphic to enlarge.)

Under the deal announced on November 15 in announcement letter 311-168, IBM is giving customers who buy up to eight SSDs a freebie SSD backplane for the System x servers, as well as a promotional price of $616 for the 50 GB unit and $2,079 for the 200 GB unit.

Both of these drives are based on multi-level cell (MLC) technology, which makes them more suitable to the wear-and-tear of enterprise environments and better than the single-level cell (SLC) predecessors in the eXFlash drives. These latest drives were announced by IBM back in April for use in both System x rack and tower servers, as well as in BladeCenter blade servers. These drives consume as little as 1 watt operating and deliver 3 Gb/sec burst rate on those SATA channels and up to 20,000 I/Os per second (IOPs) reading data and about 3,000 IOPS writing data. A typical 3.5-inch disk spinning at 15K RPM can do about 300 write IOPS and 390 read IOPS, and a 2.5-inch disk spinning at the same speed can do 250 write IOPs and 300 read IOPs. IBM is packaging these 1.8-inch SSDs into eight-packs and offering up to three of these in a 2U rack-mounted server. The 50 GB unit has a list price of $885, and the 200 GB unit sells for $3,199 normally. So IBM is chopping 30.4 percent off the cost on the skinny one and 35 percent off the fatter one–and tossing in the backplane, which normally costs $195.

These skinny SSDs support Windows and Linux operating systems and VMware hypervisors according to IBM’s redbook on them, but I don’t care. There’s no good reason why IBM i and AIX cannot run on these units or why they are not enabled on Power Systems machines. Well, except that IBM probably wants to make more money selling more expensive SAS controllers and SSDs and these units are not hot-swappable. An eight-pack backplane loaded up with the 200 GB units yields 1.6 TB of capacity for $16,632 at the promotional price, which is available until March 31, 2012, and plugs into the on-motherboard SATA controller in the System x boxes. By comparison, the feature 2053 SSD controller costs $3,054 and the feature 1996 177 GB SAS flash modules that plug into them cost $4,400 each. You need two controllers and eight drives to get 1.42 TB of flash capacity and that will run you $41,308. That’s a big difference in price for price-conscious customers in the midrange.