We now look at the total system power consumption. We obtained these results using the efficient 220 W Fortron power supply. Using a power supply unit that is rated for a higher output will automatically increase these numbers by a considerable amount.
The idle power is almost identical. Our Core 2 Duo E7200 system on the Foxconn G31 motherboard utilizes 31 W idle power when running on two DDR2-800 memory modules. Since many Atom solutions only support one memory module, we decided that power optimization achieved by removing one DIMM wasn’t a bad idea. Please look at our article Parallel Processing, Part 2, which compares performances of single- and dual-channel memory configurations.
Peak power consumption is higher than just the difference of the Atom processor’s 4 W TDP because processor tasks will automatically involve other system components. A peak power value of 36 W for the Atom 230 machine is an exceptional result, as it allows power requirements to be calculated more precisely than it does for other systems. The Core 2 Duo E7200 test system went up 29 W to 54 W, which represents an 86% difference. However, if you remember the performance difference between the Atom 230 and the Core 2 Duo E7200 on the last pages, it’s obvious that the Core 2 Duo delivers up to several times more performance at a power requirement increase of 86% maximum. The performance increase is proportionally higher than the power requirement increase in any case.