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how much power savings can Speedstep give?

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I got an E2180, Max TDP 65watt.

Riddle me this. If speed step is enabled, what kind of wattage will this thing be using running at 1200mhz (6x multi), instead of 2000mhz (10x multi)?

This would be for idle cpu time only.

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Don't forget the significant drop in vcore.

Reply to randomizer

Simply, your not going to see a difference on your electric bill.

Normal use, you prolly never see your E2180 hit and maintain 65W TDP. One program that can touch the TDP, is prime95 when it's doing the FPU 800000 iterations. I normally see hottest temps when its doing that test. So even when prime is running, its not going to push it to its TDP constantly.

Whether your machine is idle at 1.2ghz or 2ghz your wattage usage will be low enough not to really make that much of a difference. The main purpose I use speed step is to get cooler CPU temps, and perhaps lowest vcore.

And besides all that, if you pair a 8800GTS (or similar) with that 2180, you might as well kiss good bye to any power savings, even at idle.

Reply to Grimmy

If you are wondering how much money it will save you on your electricity bill, it will depend on a few things.

I would say the difference with and w/o SpeedStep is about 30w per hour under normal usage. Let's assume the PC will be on 24/7 and there are 30 day per month. That works out to a savings of:

30w X 24 hours X 30 Days = 21,600w = 21.6KW of power consumption for the month.

I pay about $0.21 per KW, so for me the works out to about $4.32 difference on my monthly electricity bill, or roughly $51.84 for the entire year.

------------------------------ Q9450 |Corsair XMS 4GB DDR 800 | ABit IP35 Pro | HD 5850 | Audigy 2 | Seasonic S12 550 | Cooler Master Centurion 532 | NEC LCD2690WUXi and Planar PX2611w | WinXP

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Reply to jaguarskx

It's even better for me, we pay $0.30/kWh here.

Reply to randomizer

business desktop idles around 100 watts for 17" lcd monitor and box, then you add video cards, drives, second monitors, etc.

the savings are not significant until you add up the whole picture at idle. box, monitors, speakers and accessories, turning them all off except my box at idle with speedstep will go down to idle at 85 watts at 120v through a UPS. turning off speedstep idle is at 117 watts. entire system with 2x22" monitors on and speedstep disabled= 296 watts at idle. using the system peaks over 400 watts out the plug without stressing the video card. just tool around with that information and save power if you like.

------------------------------ If you don't know what OS/2 is, you don't understand.
Reply to rockbyter

rockbyter what cpu are you using?

Reply to nowwhatnapster

You can also lower your cpu voltage manually on some boards in the bios. I got mine down to .975 volts on a celeron and windows still ran pretty stable, and speedstep still works. But I think the biggest power user is still the video card. I use onboard video or a low end card; I'm not a gamer so I don't need an 8800gt.

Reply to o1die

Coincidentally, Anandtech has just released an article covering that :)

I was quite surprised, but it seems that on a CPU like yours, Speedstep should only make a <5W difference, in other words: none.

Reply to tim851

And I believe this is the link Tim851 was referencing...........
http://anandtech.com/casecoolingps [...] spx?i=3413

The savings are minimal for a single computer.

------------------------------ If its good in theory but not in practice,
its not good theory.
Reply to zenmaster

Heh.. if memory serves, my old P4 3ghz paired with 6800GS AGP idled at 115-120w.

 

My E4400 idled at 109-111W with a 7300GT (my dad's old video card for testing).

 

When I hooked up the 8800GTS 320mb (G80) it idled at 160W, with the E4400. Then I got my Q6600, and in the same process, replace the G80, with the 8800GTS 512MB (G92) and PSU Corsair 620W. From there, my system idled at 150W.

 

Of course having a load on it is a different story. I use the P3-kill-o-watt meter for those past readings. So even having a Q6600, my idle temps are not much different from my E4400. And using the S3 power management, putting the system asleep also helps power consumption to a min, as well as bring up the system faster.

 

Since I use 2 UPS's, my total power draw from everything is around 420-500watts (load).


Message edited by Grimmy on 09-22-2008 at 03:20:26 PM
Reply to Grimmy

the range of power numbers i gave was a q6600 at 3.2, x1950 pro, 6 hard drives, dvd burner, tv tuner, total of 13 - 120mm fans. Logitech 5.1 x530, viewsonic and envision 22" monitors, 2 cheap powered usb hubs, keyboard, mouse, whatever. it all adds up.

------------------------------ If you don't know what OS/2 is, you don't understand.
Reply to rockbyter
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