Compute nodes were packaged two per compute card, with 16 compute cards plus up to 2 I/O nodes per node board. There were 32 node boards per cabinet/rack. By the integration of all essential sub-systems on a single chip, and the use of low-power logic, each Compute or I/O node dissipated low power (about 17 watts, including DRAMs). This allowed aggressive packaging of up to 1024 compute nodes, plus additional I/O nodes, in a standard 19-inch rack, within reasonable limits of electrical power supply and air cooling. The performance metrics, in terms of FLOPS per watt, FLOPS per m2 of floorspace and FLOPS per unit cost, allowed scaling up to very high performance. With so many nodes, component failures were inevitable. The system was able to electrically isolate faulty components, down to a granularity of half a rack (512 compute nodes), to allow the machine to continue to run.