Power Measurements
We conduct every power-measurement test with all processor power-saving features (DES, EPU, and others) enabled, and we perform each test twice—first with the motherboards’ proprietary power-saving features disabled, then with them enabled. We select automatic power-saving modes where possible.
Idle Power
Most motherboards show a similar idle power. Remember that these results are obtained with processor power savings enabled, but without each motherboard’s power-saving features enabled. MSI’s P45 Diamond is the only product that ekes out a noticeable decrease in idle power consumption with its power-saving features enabled; the others provide minimal savings. Also keep in mind that the motherboards by ASRock and Foxconn don’t offer any power-saving features.
Remember also that we used a Core 2 Duo E7200, which is an extremely efficient, 2.53 GHz, 45 nm processor. This represents a major challenge for the test motherboards, as they have to save power where power consumption is already low.
Peak Power
The Core 2 Duo E7200 processor shows a gross power-requirement difference of approximately 30 W between idle and peak states on our test system running Windows Vista. The MSI and Gigabyte motherboards manage to show a noticeable difference using their power-saving features. Asus fails at peak processor power requirements, as the system requires 1 W or 2 W more power with EPU-6 enabled in Auto mode than with EPU-6 disabled.
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Wow, the ASUS power management features really are a mixed blessing...The MSI board is the only one showing real improvement in power consumption.
Would it be possible to test the boards power consumption with a quad core CPU as well?
Indeed, I never understand it's always about the extremes... You have to be either a crazy overclocker seeking maximum performance or an absolute greeny seeking minimum energy use... Why can't you be a sensible person seeking reasonably good performance with a reasonably low energy consumption? I am indeed planing to buy a mid-range (Q9450) quad processor because I need the processing power, but i still want to keep my overall energy use as low as possible. Am I the crazy one?. I've seen other reviews before showing that GB and Asus products do decrease energy use in such configurations, but I would have liked THG to check it out as well...
Slomo and daniel, I agree, especially the comment about the extremes. That is a word I don't think anyone would use to describe me, and it is the more general and practical information I look for (and try to offer) at THG and on the forumz.
rbcsod, I don't have any of the problems on any of the systems I use to access THG. Whatever valid editorial complaints you may have, be careful of making technical ones until you've checked your own system and settings.
The intro makes it seem like the main factor for energy efficient computing is the environment. What about those who don't so much care for the environment, but like the idea of less energy being wasted in the form of heat, which reduces the number of fans you have to listen to constantly.
Will, I couldn't get my Asus P5B Deluxe/WiFi-AP board to lower E6400 CPU voltage at idle. It would reduce the multiplier from 8x to 6x but still maintain the 1.3125v core voltage. I now just run the CPU at 2.56Ghz @ 1.125v.
I wonder if the power saving features work when overclocking and which would be the best in that scenario. That would probably be a bit more relevant for a good majority of us.
oh well... my work gets to pay the power bill on this one 
Find the best overclock that all of the boards can handle and test the power savings/ usage then.
I don't know if you all have time, but a follow-up article covering this would be great.
Still good article though guys. I actually just bought an ASUS P45 board and wish now that I got the MSI...
great article. very informative. would it be possible to try out the newer gigabyte p45 ultra durable 3 boards? i would love to know how their power consumption fares compared to the gigabyte board you tested here.
Watt-Hours is a unit of energy not power.
"The MSI P45 Diamond requires the least power (118 Wh) in terms of Watt-hours consumed by the test systems to complete a SYSmark 2007 run"
should be
The MSI P45 Diamond requires the least ENERGY (118 Wh)...
power (measure in watts) gives you the rate at which energy is expended
which is different to energy (watt-hours)
Good stuff!
A note about other power saving measures, such as an efficient PSU and video card, etc. might have been good. I did suspect this was true, but I'm glad to have some research to back it up.
It's sad to see the power-management features that some manufacturers advertise as "ultra power efficient" are not quite as they should be. However, it's nice to see that the current trend goes towards green computing. You don't have to be a tree-hugging hippie, a cheap consumer who wants to save on his power bill or a low-noise freak to seek a good power/performance ratio. It's all about balance, like danielgr suggested earlier.
Considering Quad Core processors are the thing of the future, and becoming more popular by the day, you'd think Tom's would have thrown in a Q6600 or something to test energy efficiency with it as well. Limiting the test to a Dual-Core is only half the market. Sure they are less power hungry than quads, but we have to realize Quads are becoming ever popular.
Just based on this test however, I'd probably either skip out on buying one of these motherboards completely, or go with the MSI board. Then again, I'm a Quad Core user, and still don't know how much affect any of these boards would have on quads since Tom's didn't test that...
Choice of components makes a huge difference here.
You have an 850watt power supply hooked to a system that never pulls more than 140 watts from the wall. so your running the PSU at 15-16% of its rated load.
Recall from your previous PSU article, how well things performed at 20% or less load -- in short, Lousy.
I say re-run the test with a 300 or 350 watt PSU and you'll see some differences as the PSU will be at around 50% load and will be running much more efficently. Less waste heat, less power needed for cooling and less overall consumption.
I agree with Kittle. PSU efficiency should be taken into accout for this test. The efficiency varies at different load levels and using a large PSU on a low end system isn't a very good comparison.
Oh, was thinking about that too. Efficient motherboard is nothing if it uses an inefficient power supply. An example would be using 400 watt power supply with a system using only integrated graphics.
Hope Tom's could test something like that.
So what you boys are saying is: If I can save 1 watt at $.07 a killowatt-hour running 24/7, I would save the planet and a whole nickle a month.WOOHOO
Um...
So where's the class action suit for false advertising? If it says energy efficiency, I expect something more than a frigg'n watt. My green harddrive at least only uses 4watts for chrissakes.
Cheers,
If the Consumer Protection Agency had A) one clue, B) a pair of gonads, and/or C) more than half an ass, companies like Raidmax, Coolmax, and Apevia would have long since been fined out of business, or at least be unable to peddle their ordure in the USA.
This article was about mobo power saving though, above and beyond, or independent from, reductions in energy usage that can be achieved with an efficient PSU. I'd like to have seen quads tested too, to see if any of the reductions scale with the number of cores.
The Asus board used more power under load with EPU-6 enabled because the EPU-6 software on auto overclocks the CPU 3% under high load by
default. This can be set as low as 1% or as high as 30%. Also on the auto setting the system down-clocks 1% to 50% in idle.
It is a simple Bus Speed OC. I have an Asus P5Q pro and am enjoying this feature as I can do an easy OC if I choose to but the system will only be in the higher OC state when the CPU power is needed. I've only tried as high as 15% though and would probably want to set more in the BIOS if I went higher.