USING A COMMERCIAL SYMMETRICAL MULTIPROCESSOR FOR LATTICE QCD

In its evolution, the computer industry has reached the point when con siderable computing power can be packaged on a single microprocessor c hip. At the same time, costs of designing a computer system around suc h a CPU are growing. For these reasons we decided to explore a possibi lity of using commercially available symmetric multiprocessors (SMP) a s building blocks for the LQCD computer. Careful analysis of the archi tecture allowed us to build a QCD primitive library running close to t he peak performance on the UltraSPARC processor. As a result, multithr eaded QCD code (both the heatbath and the Wilson fermion inverter) run s at about 50% efficiency on a single SMP. The communication between d ifferent CPUs is handled by a coherent memory system. Currently we are planning to connect several SMPs with a high bandwidth network into a single system.