I fail to see how cray using windows can be more powerful than a cheaper self built cluster using supermicro/tyan blade barebones running linux
Indeed. And I expect there would be lots more software (and technical experience) for *nix based clusters. The thing I haven't seen is any description of the interconnect between the nodes. Interconnect speed and latency is really important for a lot of applications of these things.
From their website (http://www.cray.com/Products/CX1/Product/Specifications.aspx): IBS12DDR/IBS24DDR 12 or 24 Ports InfiniBand Switch IBS12DDR - Twelve -4X 10/20Gbps (SDR/DDR) CX4 ports with support for optical adapters and cables - Subnet Management Software - Embedded Management with Linux OS with Ethernet and secure shell access - Ultra-Low Latency < 180ns ... That's the blade-to-blade latency, right? Sounds fast...