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Huge success undervolting the Air!

silverblack said:
My settings are as follows for my MBA

800 MHz 0.9000 V
1200 MHz 0.9000 V
1400 MHz 0.9000 V
1600 MHz 0.9125 V

I am under the impression that the CPU power consumption is only defined by the voltage and NOT the frequency.

In other words, am I better off deleting the 800 and 1200 MHz lines in the settings, forcing my MBA to run at minimum 1400 MHz (since power-wise, it's the same as the lower speeds)?
Click to expand...

great question. in regards to coolbook and setting v and mhz, does voltage alone determine battery life or does freq have an effect. only the voltage should determine power consumption but i'm sort of wondering what really happens with battery life. if it's only voltage then just drop 1200 mhz and 800 mhz since they're at the same voltage as 1400.

what are you guys seeing on battery life with these parameters.
 
pughchrism said:
great question. in regards to coolbook and setting v and mhz, does voltage alone determine battery life or does freq have an effect. only the voltage should determine power consumption but i'm sort of wondering what really happens with battery life. if it's only voltage then just drop 1200 mhz and 800 mhz since they're at the same voltage as 1400.

what are you guys seeing on battery life with these parameters.
Click to expand...

I've been using those settings for over two weeks and haven't noticed a great increase in battery life but it definitely runs cooler. I did not had core shutdown prior to using coolbook.
 
I have been using this program for a while now. So far, I'm quite pleased with it. It has for sure reduced the temp and times the fan kicks on. I don't know about battery life, but I would suspect it could be saving some time. Maybe I will recalibrate my battery sometime and do a controlled test.

The lowest setting that I use is 600MHZ when on battery and it seems to run fine. I don't know how someone could damage the processor doing all of this since it seems to limit the range of settings anyway. But I sometimes wonder whether it is good for it to be bouncing around between 0.6 to 1.6 GHZ?? I'm glad that I have AppleCare.:)
 
It's supposed to do that

The ability to throttle down the processor speed to save power and generate less heat is built in to the Core 2 Duo. Coolbook just takes advantage of the ability to change particular settings. Notice that there are already default voltages set for the various frequencies? That's what the Air was doing went sent from the factory.
 
factory settings

when these units, i've tested 3, come from the factory i've experienced stuttering video, lost hd episode, and high heat. tweaking with coolbook is night and day difference from the factory settings. for example, i am seeing 25 degrees C less heat when both of my cores are maxed for an extended period of time AND i don't see any stuttering on any video. i was able to reduce my 1600 mhz to 0.925 v, 600-1400 mhz at 0.9 v.

my first unit - ran pretty hot, stuttered video after ~ 30 min, would start shutting down the cores under heavy video loading even though the temp was only ~ 69 C. i didn't know about coolbook

second unit - didn't run quite as hot as the first unit, video under load would stutter. coolbook fixed all of that with no video stuttering and significantly reduced temps. 1600 mhz at 0.925 v, 600-1400 at 0.9 v

third unit - runs very hot, video under load stuttered. coolbook fixed all of that. 1600 mhz 0.925, 600-1400 0.9 v. reduced 1600 mhz full load from 105 C to 80 C.
 
This is really sad that the mba has to be undervolted to get better performance... since I've sold my mbp that's on my sig I'm very very interested in an ultraportable now just for webbrowsing.. I'm looking at the air again and heavily looking into these forums..
 
jjahshik32 said:
This is really sad that the mba has to be undervolted to get better performance... since I've sold my mbp that's on my sig I'm very very interested in an ultraportable now just for webbrowsing.. I'm looking at the air again and heavily looking into these forums..
Click to expand...

As I posted earlier, CoolBook has done little to nothing for me. My computer still is in the 50-60 C range for "wifi productivity" and fans still go to 6200 very often.
 
would coolbook help me???

i just d/l coolbook but haven't activated it yet. i used it to monitor my Air and here's the settings of the machine

if 0.9 V is the lowest and most of the time my machine runs at 800 MHz, coolbook won't do me much good would it?
 

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1appleAday said:
i just d/l coolbook but haven't activated it yet. i used it to monitor my Air and here's the settings of the machine

if 0.9 V is the lowest and most of the time my machine runs at 800 MHz, coolbook won't do me much good would it?
Click to expand...

Theoretically at the 800MGZ is the only preset that has the same voltage... but I'll tell you.... set your processor to run at 1.6 and at the preset voltage of 1.15... and put the cpu bar to 10 and let it run for about 15 minutes... you'll see your temp reach 90 to 100 in that time.... after, that set it to 1.6 at 0.9125(the lowest I can get my cpu without kernel panic) and run the same test... You won't see it jump over 80-85.... so yes it makes a difference...

on the low end, you won't notice much, but start running VMware or encode a file or start watching High def movie trailers, and you will notice a huge difference...
 
I agree

Coolbook won't do you any good if you never do anything but read email or surf the net. But it will decrease the heat buildup enough to keep the machine from overheating and dropping a core when you do something processor-intensive for a prolonged period. I can encode movies with Handbrake without it overheating.
 
thanks for the replies. i'm by no means heavy user. what bothers me is, like many others, the fan noise, under light use! however, the usage questions gets more complicated when syslog.d comes into play (see another thread about system.log for details if you want). in other words, my personal usage maybe light, but if the system process is taxing the CPU, than i can't help it (other than killing it i guess).

there's another thread about removing excessive thermal paste. i wonder which would help me more. in terms of "difficulty", i guess trying coolbook would be easier than cleaning up thermal paste...

for those of you that coolbook doesn't help addressing the heat/fan issue, anyone has the guts to open up your Air and see if thermal paste is the culpluit here? (i don't... :()

this is my first mac. i still like my AIR, and i understand it's a rev A so there's risk. i still don't regret my purchase (since i've read all the issues b4 i pull the trigger), but i can't help but saying this: i bought 2 dells in the past and both of them "just work" out of the box :rolleyes:
 
1appleAday said:
there's another thread about removing excessive thermal paste. i wonder which would help me more. in terms of "difficulty", i guess trying coolbook would be easier than cleaning up thermal paste...

for those of you that coolbook doesn't help addressing the heat/fan issue, anyone has the guts to open up your Air and see if thermal paste is the culpluit here? (i don't... :()
Click to expand...

I say do the "trifecta". Clean off the gunk. Apply coolbook. AND apply SMCFancontrol and set max speed to 4 or 5k.

Anyone know if coolbook and smcfancontrol can work together? I don't see why not.
 
Installed on my MBA and used the setting that most Air users have done here.

I have been browsing Time Machine for 5 mins and just general non-heavy work on the laptop.

CPU idle 90%
Temp 50 degrees

Why oh why is my fan running at 6000 rpm?
 
I agree it's pretty annoying to have to fix the overheating issue ourselves--for $1799 Apple should have made sure it was handled ahead of time. I think they rushed it into production using a CPU that generates more heat than the case design can dissipate. The new thinner processors supposedly available later this year will probably help. At the very least, Apple could be sure the thermal paste is properly applied. I'm leery of opening mine up like that--and I'm not sure how much paste is SUPPOSED to be there anyway.
 
The CPU is not the only thing that generates heat. I've found that my fans kick in also when I'm using the network card heavily (time machine backup on wireless) or the video card (browse time machine, you tube, etc.) even when using coolbook.
 
smaug said:
The CPU is not the only thing that generates heat. I've found that my fans kick in also when I'm using the network card heavily (time machine backup on wireless) or the video card (browse time machine, you tube, etc.) even when using coolbook.
Click to expand...

how high does the fan kick in though? rising from 2500 to 4500 is ok, but from 2500 to max then coolbook is not helping in that regard.
 
I have been running the app (registered) for 2 weeks now

Yes it works, BUT I still had issues with the fans going all the way up to 6200 and taking for ever to come back down.

I read another post (4 days ago) about (just like the first gen mackbook), too much thermal paste being applied.

After I fixed this issue, I have now been running cool and quite.. No Heat No Noise.

I have all speeds set to .900 and throttoling on... what a difference.. (also added the additional speeds)

I run VMWARE, ENTOURAGE, and lots of video apps...coool :)

(I also use fan control to set it at 2000 as min)
 
Bah! Mine is much better!!

Tool- RMClock

Scanario 1-
Account - web surfing.
Backgroud processes-
Antivirus, Transparency, Dock with big PNG Icons, 3D effects (WinFlip), Yahoo widget engine with 10 widgets (Including a Big Animated Analog Clock)

Foreground tasks- Opera, Yahoo messenger, MSN, Rediff, Skype.

RMClock profile-performance on demand.
All Mulitpliers at 0.95V (the minumum option) 6X~10X
Systmem Rock Solid!
Usually runs at 6X (1ghz)
Core temps- 23.C ~ 33.C

Fan/Noise -Absent.
Graphics temp- ~40.C

Scenario 2-
Plain undervolting

Background tasks- Minimum/Absent
Foreground - Game (NFSMW,DOOM, Call of duty etc)

Multiplier 10X 1.667 Ghz at 0.96 (Just a Notch higher Than Min)
Lower Mulitpliers at 0.95V

Aquamark score - 43K
Temps 50~60.C
Fan at low sppeds
Graphics temp 50~60.C

Before Undervolting-
Multiplier - Switches 10X 1.667Hgz at 1.26V and 1Ghz At 0.95V
Websurfing Temp- 40~58.C
Gaming temp- 80~90.c (Ouch! My pants!)
FAN- Huh! Its better called a Hairdryer!

Config-
1>Custom HP DV 8/9XXX series (Import
from Singapore)

2>17.2 in Widescreen, 1400X900
Dual lamp,Ultra bright (OMG!!!!!
Gorgeous!!!) 5:3 Aspect ratio

3>Intel Core QUAD, 1677Mhz,667
Mhz FSB , 2MB L2 cache, 31W
socket 479

4>Intel 945PM Chipset,Pcie X16
support,Sata Support,Upto 2G RAM
support.

5> 1 GB DDr2 667 mhz RAM.

6>Nvidia GF 7400Go OEM SLI!!!!
- 2X nvidia G72 cores at 400Mhz
each + 512 MB RAM (700Mhz)each
OC'd to 564/864 For gaming Profile

7>Intel HD audio

8> 2X Seagate Momentus 7200Rpm
Sata2 HDDs (80GB X2)

9>HP DVD Writer/RAM with
Lightscribe

10>Inbuilt Bluetooth and Wi Fi, +

Dial-up Modem +100mb/s lan
11>Ports-
4X USB2
1X S-video and VGA
1X Firewire
1X PCM cia and Express card slot
5 iN 1 Card reader


Misc-

1>HP Quick play Buttons
and remote control

2>Copper Heatpipe cooling

3>Fullsize + Numeric keyboard
 
bhvm said:
Bah! Mine is much better!!

Tool- RMClock

Scanario 1-
Account - web surfing.
Backgroud processes-
Antivirus, Transparency, Dock with big PNG Icons, 3D effects (WinFlip), Yahoo widget engine with 10 widgets (Including a Big Animated Analog Clock)

Foreground tasks- Opera, Yahoo messenger, MSN, Rediff, Skype.

RMClock profile-performance on demand.
All Mulitpliers at 0.95V (the minumum option) 6X~10X
Systmem Rock Solid!
Usually runs at 6X (1ghz)
Core temps- 23.C ~ 33.C

Fan/Noise -Absent.
Graphics temp- ~40.C

Scenario 2-
Plain undervolting

Background tasks- Minimum/Absent
Foreground - Game (NFSMW,DOOM, Call of duty etc)

Multiplier 10X 1.667 Ghz at 0.96 (Just a Notch higher Than Min)
Lower Mulitpliers at 0.95V

Aquamark score - 43K
Temps 50~60.C
Fan at low sppeds
Graphics temp 50~60.C

Before Undervolting-
Multiplier - Switches 10X 1.667Hgz at 1.26V and 1Ghz At 0.95V
Websurfing Temp- 40~58.C
Gaming temp- 80~90.c (Ouch! My pants!)
FAN- Huh! Its better called a Hairdryer!

Config-
1>Custom HP DV 8/9XXX series (Import
from Singapore)

2>17.2 in Widescreen, 1400X900
Dual lamp,Ultra bright (OMG!!!!!
Gorgeous!!!) 5:3 Aspect ratio

3>Intel Core QUAD, 1677Mhz,667
Mhz FSB , 2MB L2 cache, 31W
socket 479

4>Intel 945PM Chipset,Pcie X16
support,Sata Support,Upto 2G RAM
support.

5> 1 GB DDr2 667 mhz RAM.

6>Nvidia GF 7400Go OEM SLI!!!!
- 2X nvidia G72 cores at 400Mhz
each + 512 MB RAM (700Mhz)each
OC'd to 564/864 For gaming Profile

7>Intel HD audio

8> 2X Seagate Momentus 7200Rpm
Sata2 HDDs (80GB X2)

9>HP DVD Writer/RAM with
Lightscribe

10>Inbuilt Bluetooth and Wi Fi, +

Dial-up Modem +100mb/s lan
11>Ports-
4X USB2
1X S-video and VGA
1X Firewire
1X PCM cia and Express card slot
5 iN 1 Card reader


Misc-

1>HP Quick play Buttons
and remote control

2>Copper Heatpipe cooling

3>Fullsize + Numeric keyboard
Click to expand...


and your point is... ?
 
Installed Last Night

Hello, I was having a lot of heat/fan issues with my Air and found this post last night. I downloaded, installed and registered coolbook. It seems to have dramatically affected my temps. Previous to coolbook my CPU was reading >85C with full fan speed almost all of the time. Since undervolting to what a few people on here have recommended I am now running in the mid 40's/low 50's with the fan speed back down to 2500rpm. That's a huge difference for my unit. I have read about the thermal paste issue and may go that route if needed, but with much lower temps it may not be necessary at this time. I'll have to see if I notice any differences during normal use but my initial impression is positive.

jim
 
^^ Surely your experience would be relevant if you had a macbook Air, however nowhere in that wall of text did I see one mentioned. If you want to get a day long 'workout' toting a 6kg laptop around that is your business. Other people might chose to buy an Air and do their weight lifting at the gym.

To the point of the thread, I also installed coolbook using the OP's numbers. Works great, really improved HD video playback. Where I uses to get skipping after 15 min of playing on a blanket it now played smoothly for 40 min sitting on a blanket before I went and propped it up on something after it hit 83 degrees C. Playback never faltered though.

It is unfortunate that we cant make the settings be persistent and must run coolbook after every boot. Is there any progress on a script that would auto run coolbook on boot?
 
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