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jus407

macrumors member
Original poster
Jan 25, 2008
97
0
I do not want to overclock the GPU, i want to under clock it.

Now, with that said, would underclocking it save power?

if so how do i under clock it what would be good settings to use.

I will just be using my mbp for email, internet, chat, and music which isnt too video intensive... i dont want a mb too small. and i would want a imac if i got that and i dont want to spend that much money so would it be ok and save power to underclock it and if so how much should i under clock it?

thanks!!!
 
I'm pretty sure underclocking won't save you any battery life. The current theory on how to maximize battery life is that the faster a processor gets the job done, the sooner it can return to a state of deep sleep. If your gpu is not being used, great, it will sleep. If it is being used, then the sooner it gets done the sooner it can return to sleep. That's why tests show that a higher clock speed processor actually lengthens battery life, rather than shortening it.

At least that's my understanding.
 
IF you can drop the voltage to the GPU after underclocking it, that will save you some power and heat, but the difference probably won't be worth it. Just like CPUs, every GPU has a different voltage requirement depending on how "good" the chip was fabricated. If you drop the voltage too much you're going to have stability issues.

Also, OS X does make pretty good use of the GPU, so DocSmitty is correct; letting it get the job done and go into an idle state more quickly might negate any benefit of underclocking.
 
Even if underclocking your gpu would save battery (which is questionable), the amount would be pretty dang small and it would make your system less stable. You can try aticellerator if you like and see if it works on your system, but I'd really suggest against it.

http://thomas.perrier.name/index.html
 
Thanks for the posts i wasnt sure if the GPU had a low usage mode or if it was able to decrease power consumption when not in use, thats why i asked, 512mb's is alot for me. but thanks for the help
 
I thought I read somewhere that Apple already underclocks the 8600M's in the 15" MBP's?
 
Be aware that changing the clock speeds of your CPU/GPU voids your warranty with Apple when it comes to notebooks.
 
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