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Huge success undervolting the Air!
- Thread starter Adam Ierymenko
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Bad. 800MHz seems to be sweet spot. at 600MHz, the system will need to run the CPU usage near 100% for many tasks and make the system very unproductive. I only use 600MHz if all I'm doing is iTunes and pretty much nothing else.
I noticed, the past week, I've been trying to run this CPU at max (1.6ghz @ stock voltage) as much as possible and see what happens. So far, the temps are down thanks to my heatsink mod, however, there's a problem. The fans are more and more at max. Why? The fan control apparently is more dependent on the Enclosure temperature sensor. Right now, my heatsink is modded so it transfers as much heat as possible to the lower casing (the copper actually touches the lower case panel w/o actually blocking the vents). Because of this heat transfer, the case actually gets hot, really hot. Excesses of 35 deg C majority of the times. This seems to push the fans to max as much as possible, trying to cool the base down. When the enclosure becomes cooler, about 28-30 deg C, the fan decides to die down. The CPU temp during this was barely at 50 deg C.
Well I have done the ... get rid of the thick icing cake.. and use coolbook (registered) have all the settings and run the device at lowest voltage setting from 600 all the way to 1.6. I use SM-FAn to set the MINIMUM fan speed at 2500, I have not set it up to limit the fan..
I must say that I dont even see an issue when it is running @ 600 as it will-switch up as soon as it needs to ...
So dont really understand your comment on the "at 600MHz, the system will need to run the CPU usage near 100% for many tasks" as soon as it needs to it just switches up... no lag no issues
it runs 80% of the time at 42c, even launching office 2008 apps only adds a few degrees for a sec or two, then back to 42-45..
power wise it runs for 4.5 -5 hours...
I know that there are thoes here who want to trick it out by being over smart (limiting the max fan etc), but why bother KISS Keep It Simple and Stupid..
(Not Aimed @ you mate)
so with coolbook,SMT Fan, and thermal paste adjustment... seems like the perfect lugable...
I have the 1600 HD version I hope that at the WWDC they come up with some larger drives ... which Ill get via the after market... or via the dealer here in Dubai and add it in...
Well, from what I've noticed, any OS has a completely different effect on each user.
I just formatted my air last night (because Microsoft Office 2008 decided to completely corrupt my fonts) and without any fan limiting or undervolting, my system was able to keep at a cool 45-50 deg C with the ambient temperature at above 90 deg F (it was HOT last night.. damn). The fans just mildly speed up to 6200 but quickly returned back to normal.
This behavior is unlike I've seen before. The 2 air's I've owned NEVER did anything like this w/o any undervolting or such.
And for the 600MHz, when I've used it, I had it locked at 600MHz and my cpu usage was always above 80%. Then again, I did have iChat, iTunes, iCal, Firefox (w/ several tabs.. at least 5+) Quicksilver, and some other programs running so that could've caused the high CPU usage.
I know its not an attack on me or anything, but I only limit the fan speed because of the noise. I know a 6200 rpm fan isn't much of a bother but when you're in a silent room at the office or in class or even at home, it can get really annoying. Plus, from what apparently I've found, the fans didn't need to be at 6200, a 4000 rpm fan keeps the system just as cool as 6200. From what I noticed, of course.
I'm just hoping apple will create a macbook pro with a similar design of the air. Doesn't have to be this thin but the style, I like the style. A little lighter in weight helps too like.. 4.6-5.2Lbs instead of 5.6 Lbs.
I just formatted my air last night (because Microsoft Office 2008 decided to completely corrupt my fonts
) and without any fan limiting or undervolting, my system was able to keep at a cool 45-50 deg C with the ambient temperature at above 90 deg F (it was HOT last night.. damn). The fans just mildly speed up to 6200 but quickly returned back to normal. This behavior is unlike I've seen before. The 2 air's I've owned NEVER did anything like this w/o any undervolting or such.
And for the 600MHz, when I've used it, I had it locked at 600MHz and my cpu usage was always above 80%. Then again, I did have iChat, iTunes, iCal, Firefox (w/ several tabs.. at least 5+) Quicksilver, and some other programs running so that could've caused the high CPU usage.
I know its not an attack on me or anything, but I only limit the fan speed because of the noise. I know a 6200 rpm fan isn't much of a bother but when you're in a silent room at the office or in class or even at home, it can get really annoying. Plus, from what apparently I've found, the fans didn't need to be at 6200, a 4000 rpm fan keeps the system just as cool as 6200. From what I noticed, of course.
I'm just hoping apple will create a macbook pro with a similar design of the air. Doesn't have to be this thin but the style, I like the style. A little lighter in weight helps too like.. 4.6-5.2Lbs instead of 5.6 Lbs.
Buddy, you aren't kidding. I live in San Jose and it was up over 100/F. I was up in San Fran all day today, and on the corner of Harrison and Embarcadero, literally across the street from the Bay it was nearly 90/F.
But, I'm out side in pretty warm weather typing away on my Air and it's only at 116/F and the fan is at 2494 RPM. Not too bad considering the ambient temp.
Yep, I hate this weather. I was at SF today too. In the mornings to about lunch time, it was great in a tshirt and jeans (you'd think I'd be wearing shorts now.. but I dunno where I put them
) In the afternoon, it sucked. I need to move to the Pacifica or something. I hate hot weathers. I'm in San Leandro right now and its A LOT cooler today then yesterday, but its still pretty warm.
just curious guys, but what do you use to check for stability? i use a combination of cputest and 2 instances of the "yes" command in terminal, but i have found that cputest will push my cpu temps passed 100C compared to only 80-85C when using terminal.
does not work well as with coolbook dynamic fsb is enabled (600 Mhz) but cant get rmclock to do the same..
well i just ran 2 instances of the command 'yes > /dev/null' for a good 10 hours on my mba and the temperature topped out at 102C with the fan spinning at 5000RPM and cpu voltage at 1.9V. the temperature is on the high side, but i'm glad that it won't get any higher than that.
Does anyone know how undervolting affects USB peripherals? Especially since the MBA's USB Port is non-standard.
Is the external SuperDrive usable when undervolted? Or does undervolting just affect the CPU and not the rest of the system?
Is the external SuperDrive usable when undervolted? Or does undervolting just affect the CPU and not the rest of the system?
It's running all the time once you install and restart, no need to keep loading it.
I've used USB peripherals just fine with no observable difference while undervolted.
It just affect the CPU. If done correctly everything else will work as usual.
I have CoolBook working for me. I think I have noticed that youtube doesn't send it into a shutdown---the primary reason I installed this. Instead, however, it seems to get much hotter than before, around 85C-90C. A bit odd given the name of the application.
Is this to be expected? Any reason for it? Is it really a choice of either core shutdowns or temperature of 85C-90C watching youtube?
(I have it set to 0.9-0.95V and allow throttling and set a max temperature of 85C; I think the problem is that I am now reaching this temperature; whereas previously my computer never got that hot)
Is this to be expected? Any reason for it? Is it really a choice of either core shutdowns or temperature of 85C-90C watching youtube?
(I have it set to 0.9-0.95V and allow throttling and set a max temperature of 85C; I think the problem is that I am now reaching this temperature; whereas previously my computer never got that hot)
Not needed anymore
I've been away for awhile, and not up to date on this thread so this may already be covered, but:
Coolbook fixed it for me early on, worked well for months, then started causing a lockup every couple of days. Disable coolbook, lockup went away, but it would CoreShutdown. I could have fixed it if i'd played with voltages more i gues,s but the little i tried didn't fix it.
However, 10.5.3 fixed the problem 100%, coolbook is disabled and removed and no longer needed. I think temps are about the same as with coolbook, but rock solid after multiple months.
I've been away for awhile, and not up to date on this thread so this may already be covered, but:
Coolbook fixed it for me early on, worked well for months, then started causing a lockup every couple of days. Disable coolbook, lockup went away, but it would CoreShutdown. I could have fixed it if i'd played with voltages more i gues,s but the little i tried didn't fix it.
However, 10.5.3 fixed the problem 100%, coolbook is disabled and removed and no longer needed. I think temps are about the same as with coolbook, but rock solid after multiple months.
given the same voltage setting, but different clock speed, what are the effects on heat and battery life?
I presume that if i Run it at 1400 at 0.9v then it will be hotter and also drain the battery faster than if i run it at 600/0.9v... am i correct in this?
I don't mind the drop to 600mhz as most of the time i am writing email and itunes at most and can't see much of a performance hit with coolbook set at medium throttling... just want to keep my air as cool as possible as the heat is making my palms sweaty...
many thanks...
I presume that if i Run it at 1400 at 0.9v then it will be hotter and also drain the battery faster than if i run it at 600/0.9v... am i correct in this?
I don't mind the drop to 600mhz as most of the time i am writing email and itunes at most and can't see much of a performance hit with coolbook set at medium throttling... just want to keep my air as cool as possible as the heat is making my palms sweaty...
many thanks...
The lower the voltage setting, the cooler the processor, and better the battery life. But you can't go too low as that will make your processor unstable, and result in kernel panic. Mine works fine at 0.9V for all clock speeds and I am happy with that.
The lower the clock speed, the cooler the processor, and better the battery life. But you can't take it too low as your machine will get unresponsive at too low speeds. Coolbook solves that by dynamically bumping up the clock speed when you need that extra power boost, and returns it back to the lowest possible clock speed when you're doing nothing but typing, or reading, or listending to music. I have mine from 800MHz to 1600MHz, and it stays at 800MHz 80% of the time, even when I am listening to music, running 2-3 programs in Windows unver VMWare Fusion, and chatting with someone. This could go to 1200MHz or 1600MHz when I am opening a program, accessing a file etc, loading a webpage etc.
Without the coolbook and with medium load, i used to run temperatures between 55-70 C. With the coolbook, it came down to 45-60 C. The machine feels a little sluggish when opening programs, but otherwise (I see those icons jumping a lot more on the dock).
I have been using coolbook for over 6 weeks now, and never had a core shut-down. The MBA does get unbearably hot when some program hangs and consumes 100% CPU, but at least cores don't drop off, so the computer is responsive enough to allow me to identify the rogue program and kill it.
The $10 for Coolbook is the best $10 I have spent on my MBA.
The lower the clock speed, the cooler the processor, and better the battery life. But you can't take it too low as your machine will get unresponsive at too low speeds. Coolbook solves that by dynamically bumping up the clock speed when you need that extra power boost, and returns it back to the lowest possible clock speed when you're doing nothing but typing, or reading, or listending to music. I have mine from 800MHz to 1600MHz, and it stays at 800MHz 80% of the time, even when I am listening to music, running 2-3 programs in Windows unver VMWare Fusion, and chatting with someone. This could go to 1200MHz or 1600MHz when I am opening a program, accessing a file etc, loading a webpage etc.
Without the coolbook and with medium load, i used to run temperatures between 55-70 C. With the coolbook, it came down to 45-60 C. The machine feels a little sluggish when opening programs, but otherwise (I see those icons jumping a lot more on the dock).
I have been using coolbook for over 6 weeks now, and never had a core shut-down. The MBA does get unbearably hot when some program hangs and consumes 100% CPU, but at least cores don't drop off, so the computer is responsive enough to allow me to identify the rogue program and kill it.
The $10 for Coolbook is the best $10 I have spent on my MBA.
Hey guys, quick question. Does the CoolBook app have to be running for the driver to be effective? I was hoping I could close it from my dock and keep the menu bar stats but it seems to close the whole app and I wasnt sure if it was still active or not at this point. Ah well, not a big deal I guess, just hope they can come out with a new version that doesnt need to sit in the dock.
The driver is running in the background all the time. You do not need the actual app open.
