PC PSU and Monitor Power Consumption Testing

Methodology and Results

These power consumption tests performed were tuned to only show differences in power usage according to the power supply used.  The Core 2 Quad rigs used were virtually identical, running the same load test with the same number of HDD’s (4 disconnected from power on one). The i7 machine was completely different so it could not be used in direct comparison to the Core 2 Quad machines.

The test chosen to simulate processor load was a high definition Planet Earth video that was looped. This was chosen because the Core 2 Quads performed similarly with HD video,  with the processors running at around 30-40% (see link #1).  This roughly simulated normal use of the computer over a one-hour period. Note that the two Intel Core 2 Quads, although sharing a similar clock rate, had different manufacturing processes (q8200: 45nm, q6600: 65nm) resulting in a significant difference in power consumption. The results below show that the power supply has only a slight effect on power consumption compared to the selection of efficient processors (see link #2).

#1: http://www.xbitlabs.com/articles/cpu/display/core2quad-q9400_6.html
#2: http://www.xbitlabs.com/articles/cpu/display/core2quad-q9400_11.html

Another consideration was the amount of power required to process the same task when comparing processors.  In the i7 test, the processor would always consume more power when sitting idle or under load. However, an i7 could complete a job faster than the Core 2 Quads,which means that it is still relatively energy efficient when considering the time it takes to complete a task.  Therefore the total power required to do work is fairly balanced (see link #3).

#3: http://www.tomshardware.com/reviews/quad-core-cpu,2499-9.html

Please note the absence of Core 2 Duo tests on our systems.  In link #2, the Core 2 Duo was shown to be the most power efficient,so we assumed that the it would perform better than the quads in our tests as well.  As such, we  do not have any quantitative data to show for it at this time.  If a Core 2 Duo becomes available, it would be a good idea to perform tests on it.  Additionally, the max watt and amp values were all experienced on startup (as expected) but were not as consistent as the average values.  Therefore, the more erratic readings would likely disappear if more start up tests were averaged out.

Quad Core / Core 2 Duo on Identical Rigs

Separate i7 Test

Monitors