Read an article in Äripäev yesterday about new computer-cluster of Tartu University. It’s old-fashioned classical 42-node 1U 2 x 4core setup. each node has 2 x Intel Quad Xeon 5400 = 8 cores per node, 32 GB ram and 500GB HDD, interconnected via InfiniBand. TU reports total performance 0,84 TFLOPS.
Some math (and physics):
- CPU power consumption for CPU system
42 x 2 x 80 Watts = 6 720 Watts
- GPU power consumption for GPU system
4 x 285 Watts = 1 140 Watts
- Performance per Watt for CPU system
840 GFLOPS / 6 720 W= 0,125 GFLOPS / Watt
- Performance per Watt for GPU system
7 200 GFLOPS / 6 720 W= 6,315 GFLOPS / Watt
Conclusion: GPU system uses 50 times less energy per GFLOPS than CPU system used by Tartu University.
So, its just 334 cores against my current configuration of 1440 cores. I really believe, that their choice was driven by status quo, sad, too mutch money has been spent to achieve only mediocre performance.