Power Consumption And Power Supply Impact
The Core 2 Quad Q9550S has the full 12 MB L2 cache, while the Q8200S only has 4 MB total cache memory. The Core 2 Duo E8500 runs a total of 6 MB L2 cache. In the end, the idle power difference is insignificant. All three processors, including the 2.83 GHz Q9550S, are very efficient when they idle.
The dual-core requires the least power at peak load, while the entry-level quad-core isn’t too far behind. The Core 2 Quad Q9550S boosts the power consumption from 39 W when idle to 106 W at CPU peak power, a 67 W difference. Keep in mind that the power supply adds to the power consumption with its efficiency of 82%, so the Intel low power quad core clearly stays within its power specifications.
Power Supply Impact
Here are the power consumption results measured with the three different power supplies. The low power 220 W FSP220 power supply by Fortron is the most efficient, as it was designed for low power systems. Enermax’s Pro82+ also does very well, requiring only a little more idle power—it is even more efficient with the Core 2 Quad Q9550s once you throw CPU load at it.
Beware of older PSUs, though. The EG565P-VE by Enermax is a product that is three years old. Efficiency wasn’t on the priority list at that time, which results in 6 to 11 W of additional power consumption if you use an older device. It clearly makes sense to purchase an efficient and suitable power supply if you want a truly efficient system.
Check prices for Intel's Core 2 Quad Q9400S