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Loading ...Cut Your Bills With a Voltmeter - the PCs
khenry
Next week I receive my electric bill and that will tell me how successful I’ve been in cutting my energy use during the last quarter, which has become all the more relevant with another round of price rises arriving since I bought my voltmeter from Maplin. However here’s the rundown of how my computers fared.
The eldest monitor, a ten year old Taxan CRT, naturally used the most power with a spiked cold start of around 250W and had the worst power usage of 95-100w, only losing 25w in standby – so I was right to turn it off rather than bothering to let a screensaver kick in. Even so, that’s now retired.
At least the Iiyama Vision Master 410 CRT , had a better cold start of up to 120W, then 90-100W whilst booting and then 72-75W for Windows usage – since it housed more modern Energy Star technology, it cut its power output all the way down to 4.5w when the monitor received no signal either post-shutdown or when the VGA cord was plugged into a DVI converter.
The best performing CRT was Dell’s E771, which is the no-frills model, but as well as having the 4.5w standby function, it only used 46-50W for Windows. Needless to say, I retrained my eyes and learned to love its 85Hz refresh ceiling in order to cut the power bill and it’s the only screen in use until I choose a TFT.
On the whole, the old machine, with a Barton Socket A CPU but new HSF, fans, motherboard and one less DIMM to total 1.5Gb, a single EIDE hard disk, two optical drives, soundcard and NIC, demanded 130W Maximum from my 430W-rated Antec Earthwatts PSU. When downgrading the graphics card from a 6800GT to a GF3Ti200 this fell to 99.3-106W, and finally a GF2 MX100 with passive cooling dropped the whole machine’s power to 87W low, and 100.4W high, averaging 94W. Warm reboots only drop the power usage to 96W peak, so I know that you might as well shut down properly each time unless it’s a Windows update.
For my Spring 2008 build on which games are played, the idle Windows usage demanded by my 650W Antec Earthwatts PSU started at 150W, but then when ADSL kicked in after booting this rose to 174W, then 186W when Steam loaded and sat idle, 188 when a Steam game launched (any of them), dead-on 200W on the game option screen, reaching a high of 216W when playing the game. Whenever a level changed in CSS or the ZPS mod, it would drop back to 200W, then 182 as the level loaded, then on a new level there would be a low of 213.7 back up to 217.8W depending on the size and detail of the Steam level.
Naturally, a more demanding game engine like those used by CoD 4 and Crysis would use even more power than this (see issue 58 for the relevant table). If you chose an Intel CPU and a current generation graphics card like a 4870/X2 and above or GF 280/+, you can consult issue 61 for the increased power consumption while testing. When taken as a whole, I’ve certainly proved that you don’t need Sizewell B to power a midrange-to-budget PC where more than one component has been designed with energy efficiency in mind. You don’t have to miss out on optimal speed when on a budget either, the power usage would stay low when using a GeForce 9600GT instead of my Radeon 3850, even if a third-party cooler might add a few watts.
One strange event that occurred was that when booting the new build to Windows, if I wait until it’s finished booting then plug the converted monitor into the DVI port, my PC reports a 100Hz refresh rate despite my knowing that the Dell screen’s physical maximum is 85Hz. I’m not sure if I’m forcing it beyond its specification or whether it’s a reporting issue in the vein of 32-Bit Vista and 4Gigs of RAM, but at the moment, I’m not complaining!
My speakers were the biggest surprise and disappointment, they are identical Yamahas and work really well, but sadly when plugged in and switched off, their two adaptors were wasting 10W in total, even when unused. So they’re now unplugged and I’ve substituted them with headsets plugged in to the soundcards directly. These let me have sound and carry on gaming or listening to podcasts or radio shows, but without that wastage of power. Losing the hum of the speakers has also helped the older machine become near-silent.
As for other external equipment, my HP printer only peaked at 22W when self-testing or spooling paper to print, in standby it dropped to 2.6-2.7W. For a Deskjet that’s 8 years old, that wasn’t bad. Same story for the scanner, which sat idle using 4-5W and only kicked into double figures when doing final (not preview) scanning. Even so, without an off-switch I unplug it anyway so there are no external peripherals which have any further effect on power usage.
All of this testing shows that it’s not worth using my games machine for straightforward web and Windows work, when I could save 50W using the less powerful PC. Overall, my computers, even when used simultaneously, have been relegated to third place behind my oven and iron for overall energy usage.
Conclusion
The reason for the big long previous post was to show that if you curtailed your wasted power on all your white goods and other devices in the home, your PC usage will have a lower impact on the final bill. You could still do almost anything apart from folding with your computer, without necessarily needing to cut down on using your machines. My final post or edit regarding power consumption will feature the bill as I receive the total next week, even if it’s the quietest time of year and the challenge will be to keep the figure low when reaching Autumn and Winter.
A lot of words there. I have also been reducing energy consumption. My core duo E6300 is normally overclocked 93% to 3.6ghz. On the mains meter that equates to 217 watts idle and 274 watts in a 3d game.
That’s excluding the 80 watts my old CRT uses.
I have now made an UNDERCLOCK profile in the bios. With this I can reduce the speed of the E6300 below its default 1.86ghz down to 1350mhz idle and 1500mhz loaded (EIST).
With this underclock I can reduce the core voltage to the absolute minimum the motherboard will allow: 1.07v
Power consumption thus falls to 139 watts idle and approx 170 watts load. A massive drop in consumption. That still leaves the problem of my 17 inch crt which consumes 80 watts idle and load. I should buy a 22 inch LCD but I read that LCD monitors actually contribute to global warming during their manufacture process.
My GPU is an 8800gt.
I should say that my underclock is fine with Vista x86 and runs spore smoothly. For a demanding 3d game I would switch back to 3.6ghz overclock.
P. S.
Since 1350mhz is very slow for vista, I have overclocked the ram to 900mhz otherwise the performance would be very poor.
My 3.6ghz ghz overclocks the ram by 230mhz (a speed of 1030mhz).
If the subject of this blog had been games you’d have received many more responses.
Just shows to go how totally disinterested custompc readers are in saving energy!
It’s all perspective, despite my posts if one device uses 10W more than another that’s when I stop caring, because it’s like having a lightbulb on at the same time. I’ve never switched suppliers, they’ve all been taken over one by one and combined by EDF, so I can see the times when really I should have been tougher about turning things off and not cost myself that money. The mains is off to everything except the PC as I’m using it to post this comment, and the fridge. The savings are going on Crysis Warhead! 