Overriding Intel SpeedStep(0.9/0.9250V to 10 000V)

[eru3]

Hi.

I have not found any information onto heavy undervolting of CPU's in this forum. It works the way you set the multiplier and associated voltage. You can limit the multipliers used, in example:

x6 0.925V
x8 0.925V
x10 0.950V

The trick is that you enable SLFM voltages, which are 0.9250V for my X9000 and even lower for other CPU's. It discovers a hell lot of undervolting for our Thinkpads, which I think, is never too much due to battery life and heat My X9000 idles at 30 degrees with x6 0.925V and is stressed around 56 degrees with x12(about 2400Mhz, underclocked 400Mhz). Not to mention more than 3 hours 30 minutes of battery life(ACHTUNG! LED MOD).

Interested or we dry up the topic?

[Hans Gruber]

I wouldn't screw with the speed step. I would suggest running on power save mode in Windows 7 and using the Lenovo power manager in basic mode adjusting the screen brightness. I don't use battery stretch but you are better off using that instead of trying to disable or modify speed step technology.

If you download CPU-Z and log your CPU performance. You would get a headache noticing all the speed adjustments your CPU makes in a 10 minute period of time.

[axur-delmeria]

Undervolting is a good way to lower temps without sacrificing performance. It's especially useful in my country, where ambient temperatures over 30 degrees Celsius are normal at this time of the year.

My experience is limited to X60/61 series Thinkpads, but the procedure is applicable to other laptop models.

eru3,
What software do you use for undervolting?

[eru3]

It is the RMClock Utility with the registry tweaks. That is for underclocking or undevolting. For overclocking I tend to go for ThrottleStop.

[axur-delmeria]

I find RMClock unwieldy when it comes to making it load automatically during Windows startup since it requires admin privileges.

Did you manage to get around this limitation?

[eru3]

I am using Administrator account - even if that is not safe - and it simply starts via windows startup. Or you need to turn off the UAC, which is not much of lack of safety - unless someone really unexperienced is using the computer.

[axur-delmeria]

I am using Administrator account - even if that is not safe

It's very unsafe.

I use IBM_ECW on the Thinkpads I've undervolted. It can be run as a service so it operates properly even in non-Administrator accounts.
It's main weakness is that its voltage control GUI is very primitive compared to RMClock-- AFAIK it doesn't even detect all the default FIDs and VIDs.

To get around this, I use RMClock to undervolt, then copy the voltage/frequency settings to IBM_ECW afterward.

My problem now is that there's a Dell D630 that I need to undervolt, and the owners aren't technically-inclined, so using an Administrator account is a big no-no.

[eru3]

But why it cannot startup via Registry Tweak?

You do not have Admin previlages at all or UAC is annoying problem? Read this, might help:

http://www.overclock.net/t/1407730/winx ... ed-account

[axur-delmeria]

Thanks for the link. I finally got it to work on the D630 using the "Task Scheduler" method.

Since it doesn't appear in the Notification area, it's practically invisible to non-technical users, and thus no way for them to mess with the settings.

[eru3]

Glad it helped you.