http://www.theregister.co.uk/2008/04/23/ibm_idataplex/

This is more like idataplex competitor aimed at ultra high compute density market. Each blade can have only 8GB max RAM to feed 8 cores, and little IO, but you get so many of these discrete 2-socket physical servers in little space. Most HPC/web2.0 customers probably do not need a lot of memory so this may work out well for them. HP is charging quite a premium for this kind of density with this solution. While idataplex has liquid cooling integrated, it would be interesting to know whether there is any integrated liquid cooling at work here.

wouldnt these 128 200W servers in a rack with hp water cabinet be lower cost to own than 42 230W idataplex with their water rack - neither adds heat to data center?

The memory is 16GB per node not per blade so it would be 16GB for 8 cores

Fuzz is right, It's 16GB per server and they're not being aimed at heavy VM usage, more for compute-heavy or forced-scale-out environments.

Also in reference to the IBM iDataplex, they're not in the same league - two racks-worth of these this HP blade model equals 2048 xeon cores and 4TB of memory and are already shipping. It's hard to find details on the IBM system but it looks like they only get either 800 or 1600 cores into the same space, plus of course you end up building your environment two-racks at a time - not always 'do-able'. Oh and they're coming in July.