Undervolting my MBP (Brand new 2.8 Ghz 15")

Do You Think Undervolting is Worth It??


  • Total voters
    25

rmbrown09

macrumors 6502a
Original poster
Jan 25, 2010
942
0
Seattle
So I like tinkering with my computers. I always overclocked and undervolted my PC's, but now I'm a mac guy.

So I have CoolBook Purchased and installed, but I'm not sure where to start, and what to do.

Just as a note, I have accidental insurance, but I'm 99% sure you can't really hurt your notebook from undervolting, more just overclocking.
Hoping to get a nice little boost in battery life, as well as cool this sucker down.

Anyone out there have any advise or can help out? Thanks
Also, If you would like wallpaper, click HERE

 

PAC88

macrumors 6502
Apr 23, 2009
457
0
I don't understand why you would want to do this? is it purely just for fun and for the sake of experimenting? are you trying to see if it will improve battery life or something?
 

rmbrown09

macrumors 6502a
Original poster
Jan 25, 2010
942
0
Seattle
I don't understand why you would want to do this? is it purely just for fun and for the sake of experimenting? are you trying to see if it will improve battery life or something?
it's 30% just cooling it off. I like to game sometimes, and this thing can fry eggs.

But more just to be able to say I did it. (or you guys helped me do it)
 

PAC88

macrumors 6502
Apr 23, 2009
457
0
that's interesting, I've never really heard of anyone undervolting.. I wish I knew more about it so I could help you out.

this is essentially the same concept as what the new i core cpu's are supposed to do?
 

rmbrown09

macrumors 6502a
Original poster
Jan 25, 2010
942
0
Seattle
that's interesting, I've never really heard of anyone undervolting.. I wish I knew more about it so I could help you out.

this is essentially the same concept as what the new i core cpu's are supposed to do?
Ummm, more or less.

The new ix's can adjust the frequency they run at. But the Current C2D's can do that too.

When the 2.8 isn't being fully used it can drop down to 1.5 Ghz.
Undervolting is just taking the voltage of each Ghz level (can't think of a better way to say that) down.

But making sure it still has enough power there to be stable.
People have seen 10C drops after undervolting.

Undervolting isn't adjusting the speed of the processor, just the power it draws to run.
 

Nano2k

macrumors regular
Nov 6, 2009
109
0
Europe
In my opinion if the comp is not crashing I dont see the purpose with undervolting. In Windows 7 I have seen this Macbook go almost 105 deg Celsius and not crash. My previous Acer laptop would crash at 75-80 deg...

There are plenty of threads about this on these forums, use the search function.
 

rmbrown09

macrumors 6502a
Original poster
Jan 25, 2010
942
0
Seattle
In my opinion if the comp is not crashing I dont see the purpose with undervolting. In Windows 7 I have seen this Macbook go almost 105 deg Celsius and not crash. My previous Acer laptop would crash at 75-80 deg...

There are plenty of threads about this on these forums, use the search function.
I am looking for specific help on a t9600.

Also, just because your computer doesn't crash doesn't mean it's good for it.

There are tons of charts that show lifetime in hours of a component with different average temperatures. You can decrease the life of your components by 5+ years by running at ultra high temps.
 

rmbrown09

macrumors 6502a
Original poster
Jan 25, 2010
942
0
Seattle
again, wish i could help. But since I can't, would you tell me where you got your background?! :D
Thanks, the background is from digitalblasphemy, normally you have to pay but, well I like the piratebay hows that.

(you might be able to tell, I photoshoped the bottom right so the mark is gone)
 

indg

macrumors 6502
Feb 7, 2007
452
7
rmbrown09,

first be sure to get the latest v2.17 which was released yesterday.

re coolbook settings, you really only need 2 settings:
1. find the highest frequency that will run at the lowest voltage.
2. find the lowest voltage for the highest frequency.

so for example, on my 2.33ghz mbp, the frequency goes from 1002 mhz @ .95v to 2338 mhz @ 1.175v.

for setting #1, i need to find the highest frequency that will run at .95v. through trial and error, my cpu can run at 1670 mhz @ .95v instead of the default voltage of 1.0625. if i bump it up to 1837 mhz @ .95v, i will see a kernel panic or system freeze.

for setting #2, i need to find the lowest voltage at 2338mhz. through trial and error, my cpu can run at 2338 mhz @ 1.075v. if i lower it to 1.0625v and run a cpu stress test, i will see a kernel panic or system freeze.

that's pretty much all you need for the adapter settings. for the battery settings, you really only need setting #1 because you want as much power possible (frequency) using the least amount of energy (voltage).

hope that helps.
 

rmbrown09

macrumors 6502a
Original poster
Jan 25, 2010
942
0
Seattle
rmbrown09,

first be sure to get the latest v2.17 which was released yesterday.

re coolbook settings, you really only need 2 settings:
1. find the highest frequency that will run at the lowest voltage.
2. find the lowest voltage for the highest frequency.

so for example, on my 2.33ghz mbp, the frequency goes from 1002 mhz @ .95v to 2338 mhz @ 1.175v.

for setting #1, i need to find the highest frequency that will run at .95v. through trial and error, my cpu can run at 1670 mhz @ .95v instead of the default voltage of 1.0625. if i bump it up to 1837 mhz @ .95v, i will see a kernel panic or system freeze.

for setting #2, i need to find the lowest voltage at 2338mhz. through trial and error, my cpu can run at 2338 mhz @ 1.075v. if i lower it to 1.0625v and run a cpu stress test, i will see a kernel panic or system freeze.

that's pretty much all you need for the adapter settings. for the battery settings, you really only need setting #1 because you want as much power possible (frequency) using the least amount of energy (voltage).

hope that helps.
Thanks for the help just got the update, going to try this out now.

 

rmbrown09

macrumors 6502a
Original poster
Jan 25, 2010
942
0
Seattle
Alright so update (and problem)

As you can see here I have set the voltage down quite a bit for the 2.8 setting (or near it, see bottom left window, top box has the 2.8 with my setting, below shows 2.8 with default)

the fans aren't even turning on, but as you can see by the temp (97C), the thing is on fire.

What is up with the fans? am i not doing something right??

 

indg

macrumors 6502
Feb 7, 2007
452
7
your fans should be spinning pretty good when you cpu is maxed out like that. even mine spin at around 4000-5000rpm when the cpu is maxed and temps usually stay below 70c. 95c is dangerously hot.

you may need to install a third party fan control app and adjust your base fan speeds.
 

rmbrown09

macrumors 6502a
Original poster
Jan 25, 2010
942
0
Seattle
your fans should be spinning pretty good when you cpu is maxed out like that. even mine spin at around 4000-5000rpm when the cpu is maxed and temps usually stay below 70c. 95c is dangerously hot.

you may need to install a third party fan control app and adjust your base fan speeds.
I dont see how voltage adjustments would mess with the fans??

The temp is what sets the fans off yes? Unless it is a voltage RPM correlation, but that doesn't make sense.
 

indg

macrumors 6502
Feb 7, 2007
452
7
you're correct that the temperature sensors adjust the fan speeds. that's why i think it's odd that your fans aren't spinning fast enough to cool down the cpu. does it get that hot without coolbook? just seems odd to me.

also in your screenshot, it shows 2793 mhz running at 1.1875v and not using your setting of 1.15. if you see that, coolbook is not working properly.
 

rmbrown09

macrumors 6502a
Original poster
Jan 25, 2010
942
0
Seattle
you're correct that the temperature sensors adjust the fan speeds. that's why i think it's odd that your fans aren't spinning fast enough to cool down the cpu. does it get that hot without coolbook? just seems odd to me.

also in your screenshot, it shows 2793 mhz running at 1.1875v and not using your setting of 1.15. if you see that, coolbook is not working properly.
It just sits there quiet as a can be while the temperature climbs up. The fans don't kick on at all.

And yes, I apparently cant figure out how to work the sucker..
 

Nuck81

macrumors regular
Oct 15, 2009
141
0
Western Kentucky
To be perfectly honest I don;t even know where the vent and fan on my Macbook pro are located. My baby rarely even gets lukewarm, but it stays on the desk the majority of the time....
 

rmbrown09

macrumors 6502a
Original poster
Jan 25, 2010
942
0
Seattle
To be perfectly honest I don;t even know where the vent and fan on my Macbook pro are located. My baby rarely even gets lukewarm, but it stays on the desk the majority of the time....
Do some decent gaming, boot into windows, or anything really intensive GPU or CPU wise and it'll happen.

Vent comes out behind the hinge.
most of the time fan speed stays low in OSx
 

kousuke18

macrumors regular
Aug 25, 2008
185
0
Alright so update (and problem)

As you can see here I have set the voltage down quite a bit for the 2.8 setting (or near it, see bottom left window, top box has the 2.8 with my setting, below shows 2.8 with default)

the fans aren't even turning on, but as you can see by the temp (97C), the thing is on fire.

What is up with the fans? am i not doing something right??

wow this reminds me of the problem I had with my old late 2008 umbp. The fans would refuse to ramp up even though the cpu temp hit close to 100 degrees C ... poor thing continued to cook itself until the fans finally ramped up when the temp hit 114 degrees C. :eek: