How to make my desktop PC more power efficient?

[mikeymikec]

My PC spec

At the moment the CPU is undervolted as far as the mobo will let me take it and it uses approximately 90W when idle.

I'm still gaming, and I sometimes play games that are demanding enough to require something more like the 5770 as opposed to the onboard graphics (AMD HD 4290).

The easy solution would be to take out the graphics card and stop gaming in that way, but that's not going to happen Though it would probably save about 30-40W when idle.

I'm on a tight budget, yet it doesn't seem to me that say upgrading the graphics card is going to help at all, and upgrading the platform (CPU + RAM + mobo) would only significantly help when the computer is under load (I don't use the computer for anything else particularly demanding except games).

What would be great is to have switchable graphics, but AFAIK that can't be done here?

I have an ancient laptop as well with a very small screen that I only use when travelling. I also have my server / theatre PC that is hooked up to the TV, but I'm not going to use that for general browsing for security reasons.

Having the 1080p widescreen on my desktop is handy for my work (sticking two windows alongside each other has been very helpful on a semi-regular basis).

 

[lehtv]

One way to make it more energy efficient is to not upgrade it. The production and shipping of new components costs a lot of energy

 

[Termie]

^ Ha, ha, true!

But seriously, there's not much he could do - he's hampered by that older CPU and chipset.

The 5770 only uses about 18W when idle, so very little savings to be had with new cards (about 8W), but of course he could remove it entirely for an 18W savings.

Actually, your biggest savings may be in the monitor department. How old is that 1080p monitor? If it doesn't have an LED backlight, it's absolutely burning up power. I switched from an older Dell 24" to a new Dell 27" and saved 40W - at all times! Now that's energy savings!

 

[mikeymikec]

The monitor is about two years old, younger than the computer. I also have it on the low contrast setting (which is mainly for my eyes, but it probably helps with power consumption as well).

 

[mfenn]

AMD cards in the 5000 series and newer are actually quite power efficient at idle.

The Phenom II is just not very good when it comes to idle power efficiency though. Locking up those two cores should help a bit. The biggest change would be to get one of the Haswell i3's when they're available.

 

[Torn Mind]

Haswell's idle power consumption was actually improved quite a bit over Ivy Bridge. But it is not a cheap upgrade, obviously

The 7770 GHz edition or 7750 would be a sidegrade performance-wise, but they do have lower idle power consumption. According to AMD, they should pull less than 10w at idle. Price is about $70-100.

A PSU with 90% or greater efficiency could help reduce at the wall figures, but only by about 9 watts. 72/.8=90W. 72/.9=80W. 80 Plus Gold PSUs start a ~$60 and they get more expensive from there

I take it that your 90W figure is taken by a Kill-a-watt or similar wattmeter. That means that

Perhaps Kaveri might be the solution for you, although you will have to wait.

 

[mikeymikec]

The Phenom II is just not very good when it comes to idle power efficiency though. Locking up those two cores should help a bit. The biggest change would be to get one of the Haswell i3's when they're available.

I looked into this through reviews and I had the impression that the difference in idle was negligible whereas there was a benefit under load of getting the job done sooner (and so less used over the task period). Admittedly I don't know what the difference is under loads that don't have a task completion point (such as gaming), it would help if my load meter had some way of remembering the peak load figure so I could do some gaming then take a note of the result at the end.

 

[Blain]

Pull that spinning platter HD and replace it with a SSD...
Shut the PC down when not in use.

 

[mikeymikec]

I hibernate it aggressively already (if I put it into sleep mode the undervolt setting is lost until reboot/power off / hibernate resume).

I need the capacity unfortunately. I suppose I could have the disk in there as well and it can spin down more often. I've had my eye on a Sammy 840 PRO for a while, but it'll have to wait until the budget can allow for it.

 

[Termie]

Your hard drive at idle uses 7W, and an SSD would use 1W or less. You don't need to trade one for the other though. Run a small SSD as your main drive, and have an HD for storage, set to sleep in 5-10 minutes. That way, the hard drive will almost always spin down, going under 1W as well.

 

[fuzzymath10]

I think the AMD platform is hurting you the most. My i5 system with a 5750 and 16gb ram with a 160gb ssd idles around 40-50w at the wall, and this is with 120v.

In fact, even my c2q system with 7 hard drives and a 4830 (worse idle than your 5770 or my 5750) idles lower than your system.

What about the psu? That might impact your idle consumption a lot.

 

[DavidT99]

Are you looking to save energy or cost? You can spend a load of cash on upgrades that you will never recoup and your energy use at the socket will reduce but this will be offset by the energy used during the manufacturing of the products you buy. So unless you are planning to upgrade anyway then you will be spending money for no real gain.

David

 

[mikeymikec]

I'm looking to save on the cost of my energy bills. In the UK we're on 240v here.

The Corsair VX450 was a Seasonic job IIRC, so I'd be surprised if it has poor energy efficiency.

 

[corkyg]

If you have an internal optical drive, disconnect it. Turn your monitor OFF when not using it. That is better than sleep. Power down printers and scanners when not in use.

 

[Torn Mind]

You will require a platform upgrade to Haswell if you really want to cut down, but an upgrade to a 7770 or 7750 will lower idle consumption by about 10 watts.

 

[Torn Mind]

If you have an internal optical drive, disconnect it. Turn your monitor OFF when not using it. That is better than sleep. Power down printers and scanners when not in use.

If LCD monitors work like LCD TVs, the only true "off" is disconnecting the plug from the wall since standby power is necessary to power certain things such as processing the signal to turn the device one.

 

[mfenn]

I looked into this through reviews and I had the impression that the difference in idle was negligible whereas there was a benefit under load of getting the job done sooner (and so less used over the task period). Admittedly I don't know what the difference is under loads that don't have a task completion point (such as gaming), it would help if my load meter had some way of remembering the peak load figure so I could do some gaming then take a note of the result at the end.

In the second part of your post, you're referring to the race to idle principle. While it is true in general that getting work done faster will give you overall lower power consumption, the big assumption is that there is quite a lot of dynamic range between idle and load.

This is true for Intel processors and newer AMD's, but not so much for a Phenom II. The total platform dynamic range for a Phenom II X6 is something like 200% (twice as much power used at load as idle), whereas its more like 400% for Haswell.

 

[ElFenix]

what are you using to undervolt? if you're not using it, k10stat can adjust the individual P-states so you can underclock at idle, which will let you reduce your idle voltage even more.

 

[mikeymikec]

I am using the board's "CPU offset voltage" BIOS setting (set to its max, -0.0625v). Before I tried k10stat, I returned that BIOS setting to its default, however (in k10stat), the moment that I reduced the CPU's P0 state CPU voltage from 1.275v to the next increment down (1.2625v) the system immediately hung. Oddly, after rebooting the system, the utility remembered the changed setting.

I read two guides for the utility first, I have no idea what I'm doing wrong with it, nor can I see an option to manually type in a different voltage figure.

 

[Ken g6]

I have an ancient laptop as well with a very small screen that I only use when travelling.

Could you hook that to your TV and get a bigger screen?

I also have my server / theatre PC that is hooked up to the TV, but I'm not going to use that for general browsing for security reasons.

What's in that PC? As a server/HTPC, is it on 24/7?

 

[Zap]

I'm still gaming, and I sometimes play games that are demanding enough to require something more like the 5770 as opposed to the onboard graphics (AMD HD 4290).

The 4290 only has 40 cores, versus 800 on the 5770.

What games do you play?

I'm on a tight budget

Give us a number.

If you were to cut a cool 40W off both idle and load, how much would you estimate savings to be over a year?

How about an AMD A10-6XXX APU? Idle is about as low as Intel platforms, plus has 384 graphics cores. Gaming would be in-between your current 4290 IGP and the 5770. Can you live with that?

Your hard drive at idle uses 7W, and an SSD would use 1W or less. You don't need to trade one for the other though. Run a small SSD as your main drive, and have an HD for storage, set to sleep in 5-10 minutes. That way, the hard drive will almost always spin down, going under 1W as well.

This would be like upgrading to a mid-range 7000 series Radeon with 10W idle TDP. One brings faster disk speeds, other more frame rates. Both cost money. Both cuts single digit watts.

I'd hit it. :awe:

 

[mikeymikec]

Could you hook that to your TV and get a bigger screen?

It's a P3 1.2GHz with integrated graphics, so not really Its max res is 1280x1024, the TV's is 1080p, and that processor is simply too weedy for say YouTube I think.

What's in that PC? As a server/HTPC, is it on 24/7?

It's an Internet facing server (24/7), it handles my websites and e-mail so I'm reticent about using it for day-to-day stuff like browsing. I considered the possibility of running a VM such as XP with anti-virus on it.

The 4290 only has 40 cores, versus 800 on the 5770.

What games do you play?

Stuff I've played since I built this PC:

KotoR 1/2
StarCraft 2
Batman AA/AC
Street Fighter 4
Painkiller
Warhammer 40k: Dawn of War

IIRC. 1080p.

Give us a number.

Complicated by multiple factors: Self employment, no budget right now but possibly in 2/3 months, and the car's service is due.

If you were to cut a cool 40W off both idle and load, how much would you estimate savings to be over a year?

I'll have a stab at analysing my most recent energy bill when business gets a bit less crazy than it is right now (hence no replies for a couple of days).

How about an AMD A10-6XXX APU? Idle is about as low as Intel platforms, plus has 384 graphics cores. Gaming would be in-between your current 4290 IGP and the 5770. Can you live with that?

It's a lot of money to put down for a sidegrade, and also it would take my main PC (used for business and personal), out of commission for a while during building and installing. Your question regarding actual energy cost savings is definitely pertinent here, perhaps I'm chasing a pointless idea in terms of cost effectiveness.

 

[Mushkins]

It's a lot of money to put down for a sidegrade, and also it would take my main PC (used for business and personal), out of commission for a while during building and installing. Your question regarding actual energy cost savings is definitely pertinent here, perhaps I'm chasing a pointless idea in terms of cost effectiveness.

TBH, this.

Spending $100 or more on a video card that saves you a few watts in idle power is not going to save you $100 on your electricity bill in any meaningful timeframe. Having a more power efficient PC is awesome, but the real world cost difference is pretty negligible across the board, and swapping out parts specifically to bring it down is a fools errand unless you're already building a new PC or buying new parts. You'll be building a new rig before they pay for themselves in savings.

It sounds like money is tight and times are rough, I don't mean to be giving personal advice but it sounds like you'll save more money cutting costs in other ways like canceling your cable television or turning the PC off entirely when not doing business work until you're in a better place financially.

 

[sm625]

When it comes right down to it 90W idle isnt all that bad. If you upgraded to haswell you're still going to be idling at near 50 watts with no video card. So all you are really saving is 40 watts. That is $40 a year. Most households waste 20 times that much power.

 

[ElFenix]

I am using the board's "CPU offset voltage" BIOS setting (set to its max, -0.0625v). Before I tried k10stat, I returned that BIOS setting to its default, however (in k10stat), the moment that I reduced the CPU's P0 state CPU voltage from 1.275v to the next increment down (1.2625v) the system immediately hung. Oddly, after rebooting the system, the utility remembered the changed setting.

I read two guides for the utility first, I have no idea what I'm doing wrong with it, nor can I see an option to manually type in a different voltage figure.

it's been a while since i used it so i'll have to go home and see what my setup looks like. mine didn't hang while adjusting voltages iirc. my athlon II idles somewhere under a volt at an underclocked 800 MHz.


Edit: I am now using phenom msr tweaker, which is greatly simplified. Idle at 4.0 multi for 800MHz at .875v.