150W idle? You crazy?

[tom66]

I just bought an energy meter recently because we're about to move into our own place and we will finally be responsible for our energy bills, yay...

It's a £5 eBay cheapie but seems accurate, as I compared it to the 46" I just fixed, rated 470W full white power, and indeed it uses around 485W according to the meter.

So I plugged it into my PC. A fairly old custom build with 9800GT and AMD FX64 dual core 2.8GHz (not overclocked.)

Booting... using 220W... fair enough, reaches desktop... 180W... OK, seems a little high so I leave it idle for a few minutes, and find the final figure is 150W. Completely idle, and it is pulling 150W... I was shocked.

My laptop draws 15W idle (AC-DC losses) which seems more reasonable.

Just can't figure out how the computer uses 150W.

CPU usage is a couple of percent on desktop. CPU runs at around 40°C, not that hot.

Whatever happened to efficiency and low power?

Any ways to improve this?

[Topcat]

Re: 150W idle? You crazy?

That's actually about normal for the average mid-end to high-end desktop. I've got shop ceiling lights that use more than that... I'd hate to know what my desktop draws sitting idle...

[mariushm]

Re: 150W idle? You crazy?

What power supply are you using? And does it have pfc or not?

Your psu may be only 70% efficient at 150-200w load, depending what you use, so your computer may actually use only about 120-130w in idle.

20w mb
10w hdd
40w cpu
5w cpu fan
35w gpu
10w fans
5w ram
2w mouse,kb

etc etc it adds up.

My q6600 with 4gig ram and 3 hdds and 4850 was using about 170w idle, 270-290w while playing. This FX 8320 I have now, I don't know, I didn't test it.

[redwire]

Re: 150W idle? You crazy?

Older AMD CPU's use more power- the TDP for a FX64 is 125W which is pretty much the max for a chip's package and motherboard. Intel is about 65W for E8600. About all you can do is underclock/undervolt it. I find the rest of the power is used by the graphics card.

Interestingly, if you use this PC 3hrs/day at $0.20/kWhr after say 2 years, it looks like it pays to upgrade to a more efficient (<0.45micron) CPU, just saving on energy costs.

[kaboom]

Re: 150W idle? You crazy?

I just bought an energy meter recently because we're about to move into our own place and we will finally be responsible for our energy bills, yay...

It's a £5 eBay cheapie but seems accurate, as I compared it to the 46" I just fixed, rated 470W full white power, and indeed it uses around 485W according to the meter.

So I plugged it into my PC. A fairly old custom build with 9800GT and AMD FX64 dual core 2.8GHz (not overclocked.)

Booting... using 220W... fair enough, reaches desktop... 180W... OK, seems a little high so I leave it idle for a few minutes, and find the final figure is 150W. Completely idle, and it is pulling 150W... I was shocked.

My laptop draws 15W idle (AC-DC losses) which seems more reasonable.

Just can't figure out how the computer uses 150W.

CPU usage is a couple of percent on desktop. CPU runs at around 40°C, not that hot.

Whatever happened to efficiency and low power?

Any ways to improve this?

Maybe the LCD and laptop adapter have PFC, while the PS in your PC does not, and the meter is measuring VA instead.

On loads with PFC, such a meter will read very close to the real power, but a 1kVA, 5w load (extreme example) will erroneously read ~1kVA.

Use a "spinning disk" watthour meter.

(kH * 3600) / t = P

kH is a constant you'll find on the meter face, typical values are 3.6, 4.8, 7.2

t is time per disk revolution, in seconds

P is real power


Example:
kH = 7.2, load = ~2590 watts

(7.2 * 3600) / 10 = 2592

Make sure you verify the accuracy of that meter, esp if used for billing purposes!


Added
Test your meter:

Get a nice oil or film cap, a 10 microfarad, 400VDC or 250 or 275VAC. Put it across the line, after this meter. What's the reading? 0 watts (correct) or 166 "watts?" (VA)

[brethin]

Re: 150W idle? You crazy?

That's actually about normal for the average mid-end to high-end desktop. I've got shop ceiling lights that use more than that... I'd hate to know what my desktop draws sitting idle...

Agree, considering the hardware you are using you are on par for what that system will use. If you want it to use less change the setting to what your laptop is so when goes into standby and turns off everything after like 5 mins etc. A Desktop under 150w is nothing to cry about for sure.

[ratdude747]

Re: 150W idle? You crazy?

That's actually about normal for the average mid-end to high-end desktop. I've got shop ceiling lights that use more than that... I'd hate to know what my desktop draws sitting idle...

Or my desktop... the only thing energy efficient there is the GPU... but with twin 92W TDP CPUs, and 3 10k HDDs, ouchie.

[eccerr0r]

Re: 150W idle? You crazy?

Of my machines, the ones with GPUs eat power like mad. My Core2Quad with the RadeonHD 5770 and the P4 with the Radeon 8500 AIW both use more power than my Core i7 that doesn't have a GPU other than the on-chip...

[Th3_uN1Qu3]

Re: 150W idle? You crazy?

My main rig (which i've yet to get back, so someone else is paying for its consumption atm ) uses around 180W idle and close to 350W with everything stressed. 65nm C2D overclocked and overvolted, 8GB DDR2 1066, HD3870, 3 HDDs, huge heatsinks and a bunch of big, slow spinning fans. It's very quiet, but it does put out quite a bit of heat, as the power usage reflects.

If you don't overclock, undervolting will likely temper that CPU's appetite. The rest is due to the inherent differences of a desktop board vs a laptop one - first and most obvious, it's larger so it can dissipate more heat, so there's room for less efficient components. If you're bored one day, swap out the MOSFETs in the VRM for insane overkill ones, and i'm fairly sure you're gonna shave 15-20W off that number.

[tom66]

Re: 150W idle? You crazy?

The meter reads in watts. It also has a VA reading option. Computer PF is about 0.98.

PSU is a 500W Hiper (it was a freebie), it uses Teapo caps, PFC and two-transistor half-bridge. Certainly not the most efficient; but I doubt any worse than 70%. Still, 120W in the PC is excessive.

Also, the laptop uses <1W in standby, and the PC uses 10W, even if it has not booted yet. 65W laptop PSU has a 0.6PF, so no power factor correction.

I just discovered the meter I am using is ex-stock from an energy saving campaign a while back. This user is selling them off. I have more confidence in it now.

[Per Hansson]

Re: 150W idle? You crazy?

tom66, I hope this post of mine can shed some light on the situation.
Read it fully and then look into the things I tested, like C3 state idle software, AMD Cool n Quiet software, etc etc...

https://www.badcaps.net/forum/showthread.php?t=4024

[lti]

Re: 150W idle? You crazy?

My computer has a 75W PSU, so it can't draw that much power.

[ben7]

Re: 150W idle? You crazy?

^Unless it is a pow[er]max!

My laptop, at idle, uses about 7.5W for the CPU.

[Per Hansson]

Re: 150W idle? You crazy?

My computer has a 75W PSU, so it can't draw that much power.

Depends on how poor it's efficiency is.
If it where 50% efficient that would be 150W

[ben7]

Re: 150W idle? You crazy?

^^^ I'm sorry, but LOL!!!

[Per Hansson]

Re: 150W idle? You crazy?

I could not resist it

[lti]

Re: 150W idle? You crazy?

I wonder how efficient it is. I don't know how much power the computer draws, but its case gets warm around the PSU.

[severach]

Re: 150W idle? You crazy?

Any mid range 3D video card draws at least 75W at idle and 120W under load. The cheapies draw 12W-20W so try a cheapie or onboard to see how much the consumption drops. Motherboards also turn out to be very wasteful, often drawing more than the processor. Where the power goes is a mystery because I've measured boards of the same series and trim level from different manufacturers and the power consumption can be 10-20 watts different. It doesn't seem to be through the main chipset as they are identical parts and I find that the heat sinks are similarly sized and are putting out similar heat. You can get an idea of wasteful motherboard designs from the ultra low power motherboard mods on the Mux blog.

Extreme Tech: 5.9 watts: The world's most efficient high-end computer
8.5W Core i3-based desktop computer (English)


Imagine what could be done if motherboard companies would pay attention to power consumption rather than crapping out 25 almost identical models with different trim levels.

I did a bunch of power testing with my Kill-A-Watt and found that my Pentium 4 775 and Core 2 systems were drawing too much power. With the Kill-A-Watt plugged into the motherboard test bench I started watching for one that was efficient. This is what I ended up with:

MSI H61M-E23 (B3)
Celeron G530 1155
4GB RAM
Intel X25-V SATA 40GB SSD or 80GB 5400 laptop hard drive

Dell 265W 80 Plus Gold: 18W idle, 41W full CPU and 3D

That is a fully functional computer that does limited 3D graphics running at 18W idle. It isn't just the power bill that benefits. The UPS they are on will last longer.

Other testing shows that an equivalent Intel brand board would drop power consumption another 2-3 watts.

[RJARRRPCGP]

Re: 150W idle? You crazy?

With my Core 2 Duo E4500 on my Asus P5QL Pro board, got 113 W (UPS power measuring that works like Kill-a-Watt) at 2.997 Ghz with Linpack running, IIRC.

Was also with my GeForce 9500 GT.

With the FSP500-60GLN(80) PSU.

[brethin]

Re: 150W idle? You crazy?

If the 150W it uses at idle is breaking your bank then shut the thing down when your not using it. Im sure your waste much more on other device you dont even realize. 150w for a Desktop is nothing to even question for any reason.