Avalon : An Alpha / Linux Cluster Achieves 10 Gflops for $ 150

As an entry for the 1998 Gordon Bell price/performance prize, we present two calculations from the disciplines of condensed matter physics and astrophysics. The simulations were performed on a 70 processor DEC Alpha cluster (Avalon) constructed entirely from commodity personal computer technology and freely available software, for a cost of 152 thousand dollars. Avalon performed a 60 million particle molecular dynamics (MD) simulation of shock-induced plasticity using the SPaSM MD code. The beginning of this simulation sustained approximately 10 Gflops over a 44 hour period, and saved 68 Gbytes of raw data. The resulting price/performance is $15/Mflop, or equivalently, 67 Gflops per million dollars. This is more than a factor of three better than last year’s Gordon Bell price/performance winners. This simulation is similar to those which won part of the 1993 Gordon Bell performance prize using a 1024-node CM-5. This simulation continued to run for a total of 332 hours on Avalon, computing a total of 1:12 1016 floating point operations. This puts it among the few scientific simulations to have ever involved more than 10 Petaflops of computation. Avalon also performed a gravitational treecode N-body simulation of galaxy formation using 9.75 million particles, which sustained an average of 6.78 Gflops over a 26 hour period. This simulation is exactly the same as that which won a Gordon Bell price/performance prize last year on the Loki cluster, at a total performance 7.7 times that of Loki, and a price/performance 2.6 times better than Loki. Further, Avalon ranked at 315th on the June 1998 TOP500 list, by obtaining a result of 19.3 Gflops on the parallel Linpack benchmark.