Crunching Numbers, Two Ways

Oil-exploration firm CGG Americas replaced its supercomputers with a cluster of several thousand personal computers linked by specialized networking software. Here's one view of how the alternatives stack up.

Oil-exploration firm CGG Americas replaced its supercomputers with a cluster of several thousand personal computers linked by specialized networking software. Here's one view of how the alternatives stack up.

	Silicon Graphics Origin 3000	Cluster of Dell Computer PCs
Architecture	Symmetric multiprocessing, where many processors share a single operating system and access each other's memory	Parallel processing, where a computing job is split among many processors that each have their own operating system and memory
Cost of system	$2.9 million	$2 million
Number of processors	128	1,024
Cost per processor	$22,656	$1,953
System memory	256 gigabytes	Up to 2 terabytes
Pluses	Designed specifically for scientific applications that do highly complex modeling All processors can communicate quickly with all other processors, which means certain computing jobs can be done very quickly	Relatively low cost of ownership Distributed architecture decreases risk that a single processor failure will stop entire job Power can be added incrementally Often uses Linux, a hot technology for which skilled workers are readily found
Minuses	Processor failure can halt an entire computing job Adding power generally adds expense: another $2.9 million machine Experienced technicians hard to find	Setup and configuration often take several weeks Overall performance can be negatively affected by speed of the network connecting the processors Constant monitoring of individual parts is necessary; more parts means more potential points of failure Large physical space required as cluster grows; additional air conditioning and electric power are sometimes needed