Curious as to how low others are able to get their CPU's to run.
Im running an Inspiron e1505 with
-1.83 Core 2 Duo (667 fsb)
-1 Gig ram (533 mhz)
-x1400 graphics card
-wsxga screen

I was looking to get some more battery life, so I looked into undervolting on the CPU. Tried out NHC, and I had some pretty crazy results.
After running Prime 95 for a couple hours, I've determined that this CPU is stable with no performance hits, after lowering the voltage settings to 0.95 Volts for all multipliers.

Watching power consumption figures, on battery, (running prime95 to load the CPU) Adjusting the CPU voltage:
Battery drain
full CPU load, full LCD, stock voltages: 37.6 watts
full CPU load, full LCD, adjusted voltages: 28.2 watts

So a 25% reduction in battery drain, not to mention it runs cooler.
Anyone else have similar/better gains with this program?

Hmm. This is the first I've heard of underclocking. Seems interesting though. Does this program work for Intel Core Duos?

It seems to be a spiffy little program. I'm not sure it necessarily does a better job than manually switching windows power profiles, but it certainly displays some helpful information, and makes everything easy to access.

I'll keep experimenting on my e1505, and see if it actually does increase uptime on batteries.

any lucky with 64-bit compatibility? My laptop came with windows x64 pro, when i try to load the program after install, it tells me theres a failure loading the NHS driver.

I'm not exactly sure how this works. Does undervolting also decrease the clock speed/overall speed of the processor, or does it just make it more likely to be unstable?

yes, I believe it works on most true-notebook processors. Works for AMD processors too. Here's a link to explain how to do it, with another program, but I like the program NHC cause it has more options, not just CPU voltage.
http://www.nordichardware.com/Articles/?skrivelse=465

This is not manipulating the clock speed, or the speed-step architecture already used, it modifies the voltage output for the CPU itself. For instance, on mine, originally, windows could modify the multiplier onthefly from 6X to 11X. It modifies the voltage according to each step, i.e.
(approx. stock settings)
6X= .95 Volts
7X= 1.050 V
8X= 1.125 V
9X= 1.225 V
10X= 1.300 V
11X= 1.375 V
(or something along those lines, I dont remember exactly what it was)
Afterwards, I slowly dropped the voltages, and found out it was stable at the lowest possible, even at max multiplier. I modified all the voltages to 0.95V

6X= 0.95 V
7X= 0.95 V.... etc. etc.
11X= 0.95 V

Runs cooler all the time, is very stable, and considerably more battery life while playing games.
Keep in mind, every processor is different, so all manufacturers overdo the voltage settings a certain amount to make sure its as stable as possible without having to run stress tests on each computer. There is no real reason not to test your cpu, to see if it is stable at a lower voltage, the worst that can happen is that your computer will lock up and you will have to restart it and try a higher voltage setting.

The voltage settings are MB limited, I believe, so 0.95 V was the lowest I could go with mine. Some will go even lower.

So yes, apparently it can decrease stability. Makes sense.

the real question is how much more unstable does it make the processor. so far it sounds insignificant, but i doubt you've prime95'd your computer while undervolting it.

I have a 2.0 ghz core dou ad im going to try it out, but i was checkin out the website and ther eis a patch for the program for core duo and core 2 duo so if your lookin to use it it does support it

I ran prime95 for several hours with all undervolted to 0.95 V, no errors, so then I tried playing F.E.A.R. and Empire Earth for a few hours last night, still no problems.
The only downsides about doing this I have found is the slight increase in boot-up time and the extra ram it uses up, which isnt much.