Copyright by William Lloyd Bircher 2010 - The Laboratory for ...

applied to the GPU core logic, larger active power variation will occur. This will
necessitate a comprehensive power model such as that used in the CPU.
Table 5.5 Average Error
CPU Chipset Memory Memory Controller GPU Disk
Idle 0.3% 1.8% 1.2% 0.4% 1.7% 2.5%
SPEC CPU2006 Integer 1.3% 4.0% 2.3% 3.4% 0.2% 5.3%
SPEC CPU2006 FP 1.1% 2.6% 7.2% 2.9% 0.5% 4.4%
gt1 0.8% 5.3% 3.3% 1.3% 0.9% 7.1%
gt2 1.2% 5.8% 3.3% 4.4% 0.4% 8.7%
cpu1 1.6% 1.8% 12.5% 14.1% 1.0% 6.9%
cpu2 1.9% 1.9% 11.5% 13.4% 1.3% 9.2%
hdr1 2.2% 2.7% 0.8% 0.7% 1.0% 0.9%
hdr2 1.9% 4.7% 1.6% 8.6% 0.7% 2.7%
EL 2.7% 9.3% 8.5% 7.7% 0.0% 1.8%
VC 1.0% 1.8% 8.4% 11.7% 1.6% 10.6%
PR 2.5% 1.1% 5.7% 5.6% 0.9% 12.1%
3D 2.8% 3.5% 5.5% 4.7% 0.0% 10.7%
SPECjbb 1.5% 0.4% 2.0% 4.1% 0.8% 9.8%
Average 1.63% 3.34% 5.27% 5.93% 0.79% 6.62%
Finally, the disk subsystem is the one subsystem which has a higher error rate compared
the server power model. In this case the error can be attributed to the effectiveness of on-
disk and link power management. In the case of the server model, no active power
management is provided. This allows for an accurate model as the workload independent
portion dominates. In contrast the more recent desktop hard drive has a workload
dependent portion which contributes as much as 1/3 of total power. This causes
modeling error to have a larger impact. Note that the subtests with the highest errors are
also those with the highest disk utilization.
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