steve_ghan@pnl_gov
New Member
In the course of preparing a proposal for a new machine here at PNNL, I noticed that the AGCM for Earth Simulator (AFES) achieves a performance of 65% of theoretical peak performance of the Earth Simulator. That is much higher than the performance we typically see for CAM on IBM and other scalar systems, which is typically 5-10% of peak. Itis not clear whether this higher performance is due to the ES hardware or the AFES software. Does the AFES minimize use of cache so that memory bandwidth does not limit performance like it does for CAM on scalar systems? Or is memory bandwidth less of an issue for the ES?
We can answer this question by looking at the performance of CAM or CCSM on the ES. So my specific question is what is the performance of CAM or CCSM, as % of theoretical peak, on the ES? If it is high then we can conclude that the high performance of AFES is due to the ES hardware. But if it is low then perhaps CAM could be modified to perform more efficiently.
We can answer this question by looking at the performance of CAM or CCSM on the ES. So my specific question is what is the performance of CAM or CCSM, as % of theoretical peak, on the ES? If it is high then we can conclude that the high performance of AFES is due to the ES hardware. But if it is low then perhaps CAM could be modified to perform more efficiently.