Cray CTO: Linux clusters don't play in HPC

jagger writes "Linux clustering was touted as the next big thing by many vendors last week at ClusterWorld Conference & Expo 2004. But supercomputer vendor Cray Inc. scoffed at the notion of putting Linux clusters in the high-performance computing (HPC) category. "Despite assertions made by Linux vendors, a Linux cluster is not a high performance computer," said Dr. Paul Terry, CTO of Cray Canada."

Comments

Re:If it walks like a duck, and talks like a duck.

[flaming-opus]

Cray could easily be at or close to the top of the top500 list, their X1 architecture will extend that far. However, for a lot of really important supercomputing codes, it's no contest: The cray will trounce the clusters (linux or otherwise). Those #19 crays are only 256 processors. To get similar performance a stack of xeons requires thousands of processors. Some tasks just can be split appart that easily.

A cray processor has eight floating-point units running at 800Mhz. The big Mac cluster (for example) uses G5 processors which have 2 FPUs at 2000Mhz. Thus the cray has a ~40% advantage. However, the G5 processor has ~4GB/s memory bandwidth. The Cray has ~50GB/s memory bandwidth. If you have a problem that needs to do a HUGE amount of math on a tiny amount of data, the G5 will rock. If you have a problem that needs to do a HUGE amount math on a GINORMOUS amount of data, buy the cray. (for a GINORMOUS amount of money too)

Similaraly infiniband (ala the big mac) is really hot in the cluster interconnect space because it gives 2.5GB/s per node. The Cray gives you 51GB/s.
You need to move a little data, buy a cluster. You need to move a lot of data, buy the Cray.

There's no one solution for all problems.