Success undervolting P-7805u anyone?

I've read the sticky by flipfire about how to undervolt. I've never done it and was wondering if anyone was successful. If you have, what are your results? I'd like to know specifically so I can mirror what you did so I don't mess up.

 

Every chip is different.

Mine is currently undervolted to 0.9375V and running at full multiplier/speed and has been since I got it without a single crash.

I also replaced the CPU thermalpad with AS5.

Here are my temps Celsius:

IDLE:
CPU = 24
GPU = 39 - 40s (fan kicks in somewhere in the 40s until it drops back down to 39/40)

MAX LOAD:
CPU = 40 (it never goes above 40. Like... never. 100% full load for an hour or more - never goes above 40. When it gets to 40, fan kicks in and it drops below 40).

GPU = 68 - 72

I've never had my GPU go above 72, but its usually around 70.

I don't use a cooler either.

 

Thanks for the reply tonester. I still have yet to undervolt because I haven't had any time. I'll probably try it this weekend. BTW, did you undervolt just your highest multiplier? In flipfire's guide it mentions "SpeedStep Technology" which (what I gather from reading) steps down your processor when full processor is not needed. Did you undervolt for the lower multipliers too? If you did, what were your voltages for those?

I know in my first post it sounds like I want to "copy" other people's settings. I don't. I just want to hear what others have come up with so I know what ballpark I can set mine to. Don't be shy people, share your knowledge!

 

When you follow the guide, it tells you how to "lock in" on one multiplier only. I mean, if your highest multiplier works at the lowest voltage, why would you ever use lower multipliers?

Using RMClock, I just have my laptop locked into the highest multiplier at all times using a very low voltage. It saves the power, but has the best speed.

 

That totally makes sense. I have yet to do it yet but I'll keep you posted when I do. Thanks again!

 

Higher speeds use more power at a given voltage because the chip will use more amperage due to the higher switching speed of the transisitors. Locking the multiplier to the highest even at a low voltage will still use more power than allowing the multiplier to drop at the same voltage level.

 

So you're saying I shouldn't "lock in" on one multiplier

 

I woudln't, you should get lower temps and power usage using a lower multiplier via speedstep as designed. The stop grant and halt states may make the differences negligible, but it's definitely going to use less power/make less heat at a lower mutliplier.

 

At max multiplier and current undervolt (0.9375), I get the exact same temps as when it is lower multiplier (lower clock) and same voltage.

IF there is some savings in heat/power, it isn't showing up for me... so I just kept max multiplier and the undervolt.

 

I could get @ 1.13 @ 2.6 with my X7800, and 2.1 @ 3.0, the lower the chip is clocked usually you get a better undervolt, also ES's typically use better silicon as they are test models so those UV well as well.

 

I finally did it. I decided not to lock the top multiplier and used Speedstep instead, although I didn't undervolt any step lower than what the highest step's voltage. I may try to go lower with them when I get more time to test them. I used 0.9375 as suggested by tonester, thanks it's working great so far! I've attached a picture.

I'd still like to see what other people have gotten. So please, share if you like. I figured what better place than a great forum like this.