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View Full Version : Can Intel Extreme Tuning Utility be used to improve Battery Life on G751JL?



colesdav
09-02-2015, 07:26 PM
Hi,

A family member just bought a G751JL.

1. Does using the Intel Extreme Tuning Utility void the laptop warranty if I were to use it to overclock the CPU?

2. Battery life is an issue with this laptop. What would happen if I dropped the Processor Core Multipliers to 8x and the Processor Cache ratio 8x. and changed nothing else. Would this save battery life? Has anyone tried this?

I don't really want to mess with Overclocking / using this tool but I thought I would ask.

Corporal
09-02-2015, 11:15 PM
1. Probably not
2. You won't notice any difference, because you can't save anything with dropping the frequency, you will have to undervolt as well. Major part of the energy consumtion is due to the GPU being on at all times. Undervolting the CPU will probably affect your stability and won't get you any significant gains.

colesdav
09-03-2015, 08:10 AM
1. Probably not
2. You won't notice any difference, because you can't save anything with dropping the frequency, you will have to undervolt as well. Major part of the energy consumtion is due to the GPU being on at all times. Undervolting the CPU will probably affect your stability and won't get you any significant gains.

Hi

Thanks for replying. Good point about the GPU burning most power.
I guess we would need some way to turn off the NVIDIA GPU (965m) and use the CPU Integrated Graphics to save power (switchable graphics).
I have also heard of Nvidia Optimus Technology which I don't think is available on the 965M in the G751JL. Not sure exactly what it does though.

I thought that dropping the multipliers on the CPU would drop the frequency and therefore drop the power consumption.
Since Power = C * (V)^2 *f , (C= capacitance = "fixed load", V= voltage, f = frequency), dropping either f or V should help with battery life.

Undervolting would have much more (squared) effect per unit voltage change but I was just thinking since the drop from say x32 to x8 multiplier is quite a drop in frequency... it should be worth something. As you say, undervolting can cause stability issues, but I cannot really see how dropping the CPU frequency should affect the stability of the CPU itself. It should just make the CPU run slower.

Do you think that dropping the CPU frequency using these multipliers would cause system stability issues though? For example maybe the CPU could end up unable to communicate correctly with the surrounding chipset?

Thanks again for your input.

Edweird
09-03-2015, 08:17 AM
A -80mV undervolt to CPU/Cache and 1-2x drop in multipliers is about what I would do, to be honest.
If you're gonna be using your monstrously powerful computer running at a fixed 800MHz per core you might as well use an Android tablet. Has nothing to do with system stability unless you count system stability meaning everything will take 5 times longer to do.

GPU is on all the time but honestly when it's not doing anything graphically intensive it goes down to 135Mhz. That's...not very much power going in.
Decrease backlight intensity, turn off keyboard backlight etc. are probably more effective solutions...make sure you have Battery Saver mode on - you can define what % load the CPu can go up to instead of changing multipliers. For performance I have mine set to min 100% max 100%, for battery, try something like min 0% max 50%, should be enough if you're not trying to do something stupid like playing games on battery power.

XTU use for these purposes cannot void your warranty unless you start messing with core voltages or base clock settings - then it might be considered an issue though tbh how would they know what happened if your CPu just fried itself anyways...

virusce0707
09-04-2015, 08:22 AM
if you want to save power go in control panel and put max cpu performance on something else than 100% on battery I have about 30-40 % + time

Corporal
09-04-2015, 09:15 AM
Do you think that dropping the CPU frequency using these multipliers would cause system stability issues though?

Dropping voltage saves battery but affects stability.
Dropping frequency won't affect stability, but doesn't save battery either. It may actually increase your battery consumption.
Lets assume an operation you need to perform takes 5 minutes @ 3500 MHz. It would take about 22 minutes for the same operation to be performed at 800 MHz.
Even if your CPU is more efficient at 800 MHz, there are other components like GPU and LCD which will drain your battery for 17 additional minutes. That way, anything you gain by making your CPU slower is offset by other components.

Corporal
09-04-2015, 09:18 AM
if you want to save power go in control panel and put max cpu performance on something else than 100% on battery I have about 30-40 % + time
The "max CPU" setting doesn't work in windows, and if it did, it would increase battery consumption, see post above. The "min CPU" setting works though.

warryabel
09-09-2015, 06:09 AM
i looking for dynamic cpu voltage offset button or slider but is greyed out!can someone explain me this issue? i have 4720 and the latest xtu.51594

warryabel
09-09-2015, 03:46 PM
bump

Corporal
09-09-2015, 09:14 PM
If it's greyed out, it's disabled in bios. Your only solution would be to modify the bios.

warryabel
09-10-2015, 05:35 PM
If it's greyed out, it's disabled in bios. Your only solution would be to modify the bios.
and why all other in this tread can use the dynamic cpu voltage? was it renamed to core voltage? sorry no one speak about it! lol

colesdav
03-04-2016, 05:08 PM
Thanks to everyone for your replies.
I decided to simply use the Windows % CPU min and max to save battery life.
I will run some experiments using Intel XTU and post the results when I have some free time.