Underclocking mid/high end video cards

Unnecessarily Long post ahead:

I would prefer smaller laptops but since 15 inch laptops are now outfitted with 9800NV and 3850 ati cards (NP8660, msi gx630 specifically), I am too easily tempted to forego size for performance. However I was wondering if underclocking/overclocking programs like ati tray tools are still relevant? Are some of those programs not compatible with Vista, do those video cards and processors only work with Vista? I have become attached to xp...

I currently have an LGS1 with an ati x1600 (yes, old), and using ati tray tools I can manually set the clocks close to artifacting levels. I can gain an extra 40min of battery life and keep it a lot cooler, making the laptop actually useful for classes while still able to play games and the like. Is this still possible with these new gpu/cpu systems? Has power consumption increased? My x1600 does not have some ati power management tool so I don't know how well those official ones work but I guess I like the flexibility Tray Tools offered.

Would a runtime of 3 hours on those laptops mentioned above be realistic? I think I saw that the N8660 has a larger capacity battery, would that only compensate due to the gpu or could it offer increased runtime if at "meaningfully underclocked" settings?
...Moreover...Is it too early to ask all these questions?

 

Or, you know, what the hell. http://www.fudzilla.com/index.php?option=com_content&task=view&id=8416&Itemid=34

I hope a 4000 series card appears soon.

 

Yes it will. I do the same on my HD2600 under vista.

And kudos on a really pretty laptop.

 

Doesn't ATI powerplay auto downclock anyway?

 

as far as nvidia goes:

they might have improved it further in later models (?)
anyway it is all there gpu downclocking, screen dimming, power on demand etc.

i can 3 hrs easily on my 17" notebook (casual use)

 

does that mean no HD 3870 Mobility laptops ?

 

Yes it does. As does nVidia Powermizer. However, manual control is much more convinient. And you can downclock lower than what powerplay/powermizer do.

 

Yeah thanks man, I figured that would be the case, so can you disable whatever powerplay program there is and just use a third party program for either ati/nvidia cards? Having the ability to control a slider is really so much more preferable. I downclock to a few mhz away from a really fuzzy screen.

 

Yup. I used AtiTool for both my previous go7700 and my present HD2600 under vista.