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smcFanControl — Cool Your MacBook Pro
Clodas writes, "smcFanControl 1.1 is a simple GUI that lets you control how fast each fan spins on your MacBook, MacBook Pro, or Mac Mini. The temperature of my MBP when idle averaged around 63 degrees celsius. After running smcFanControl 1.1, my temperature dropped to 43 celsius within 10 minutes of use. This now allows me to sit my MBP on my lap, something I was unable to do previously since the machine got so hot. I have my fans set to spin at a minimum of 3000 RPM and I still don't hear the fans spinning. Apple by default has them set to 1000 RPM. I really recommend smcFanControl 1.1 for any that feel their MB, MBP, or Mini are too hot to handle."
I reset my fan seed to 6000 to see how cool my laptop could get, and its amazing getting cooler then most PCs I owned, whose fans are 10x as load. I would pay for this app if it was a commerial program!
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I wonder how it works, I'd love to see the source code for it
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The fans will automatically rev up to 6000RPM max if necessary to keep the machine cool, and as a failsafe, the machine will automatically turn off if it gets too hot*
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* At least, I believe it will, a lot of other PCs do, and my old mac did
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For Windows users, Speedfan lets you do this on nearly every desktop computer. For some reason Speedfan generally doesn't work with laptop computers, though.
Been using smc and then smcFanControl since they showed up... battery life on my MBP doesn't seem appreciably different, not that it was any good to begin with, with the 7200rpm HD.
The best way to save battery is to dim the screen. At less than half brightness I can get nearly 3.5 hours in normal usage. At full brightness it's more like 2.5+.
A fan's power draw is a couple of watts at most, and no, your fan won't die 'orribly from it using speed control software. :)
Higher speed probably means the bearings will wear out a bit faster though.
For more info, check out http://en.wikipedia.org/wiki/Pulse-width_modulatio n
And how long does your battery last between recharges now?
The question is whether the fans will be run past their expected/rated lifetime before the computer has.
As we all know- small fans (CPU fans, chipset fans anyone?) don't last very long. That's precisely why they're only run when necessary. Given the MB/MBP's thermal output, Bad Things will happen if those fans fail- probably no worse than it shutting itself down or crashing. Still won't be good for it.
That said, keeping the fans on a very low speed to maintain a cooler temperature will improve general component life.
Please help metamoderate.
How it works (the simplified 2 mile high view)- Sitting over inside the microprocessor is a diode, that is at the same temperature as the microprocessor chip. The forward biased voltage of a diode changes with temperature. With some signal processing, you can turn that into a temperature number.
The temperature is available for readback over a serial bus. (SMA,SMB, I2C, the original was SMA if I remember correctly) A software routine reads the temperature and makes the call "cool me off" or "at desired maximum temperature" which gets turned into a number that gets loaded over the bus back to the TAFI chip. That number gets dumped into a DAC, which becomes the voltage for powering the DC motor fan.
Presto! Variable speed fans dependent on how hot the microprocessor is!
Before that, all the PC's had fans that ran full blast 24-7-365.
Whoever did the software better realize that they are messing with the thermal management system and could seriosly fry their computer, if they set things up to not cool enough. So like any hardware hack, YMMV and you are taking a chance of doing permanent damage to the machine.
The fan motor, in comparision to the processor, does not suck that much juice, so I expect that it won't change battery run time in a big major way. A little, but not gobs.
www.effectiveelectrons.com "chips that work" Analog, RF, Mixed Signal
Seeing as how most small sized fans (40mm-ish) dont usually take more than 0.1A @ 12V => 1.2 watts (at full speed), compared to the 40-50-ish watts that the rest of the system uses the difference is negligable.
Yes.
If your screen buzzes when dim you have a bad inverter board. Unlike the famous CPU whine, Apple was willing and able to fix this problem from the very beginning. If your machine has the bad inverter, send or take it back to Apple for repair.
Well, desktop fans have yet to rip themselves apart. The software won't throttle the fan faster than it was designed to go, and all fans are designed to be able to sustain their maximum rotation speed until they reach their MTBF. Some people who use their laptops as DTR machines will have them under a constant heavy load (and then run folding in the background, just to make sure their batteries never stand a chance), and their fans aren't tearing themselves apart.
Basically, fans can be fed anywhere from 0 to 12 volts (maybe laptops are 0-5v, but it's pretty standard). It usually takes 5-6v to get them spinning and overcome inertia, but after that you can drop it down to 4v or so to keep it going. The app just overrides the software control telling it to throttle the voltage until it hits near a certain RPM. The voltage control almost certainly works on a percentage, but even if not, there's only so much available to give it - you can't just pull random extra voltage in from somewhere to overvolt the fan.
As to the relation to a hard drive... couldn't say. I've seen numerous desktop-sized fans that use quite a bit more power than a notebook hard drive, which (in my experience) draw 2.5w or less (ie, you can power them from a USB port with no extra plugs). There are fans out there that draw 12w and up, but those tend to be the high-speed 120mm fans that can do serious damage to objects that happen to get in their way. Notebooks, on the other hand, tend to use very small fans such as 40mm units, which have a power draw in the half-watt range at full tilt. Varies by fan of course, but this probably won't drain your battery any faster than plugging in a flash drive and pulling a few files from it.
I'm just a bit irked that Slashdot posted this today. Not 36 hours ago, I left my MBP at the Apple store for them to fix the heat problems.
How are sites slashdotted when nobody reads TFAs?
How much longer the battery lasts on a single charge when you increase the fans speed three folds? With laptops, battery charge is always an issue. Thus, you need to balance out the battery life per charge, the safety of the user and the tolerance of the CPU/hardware to temperature. Rightly or wrongly, Apple decided that the temperature is safe enough for lap uses though somewhat uncomfortable, is acceptable for the power saving, and the hardware can withdstand it. It has got nothing to do with the ability to regulate the temperature.
People will complain when their laptops only works 2 hours on a charge. You can then increase the battery size, but then people will complain when their laptops weigh 5 pounds and is 3-inch thick. People will always complain and tradeoffs will always be part of the design.
I am presently trying to quiet down a MiniITX machine. It has a pair of howling fans in it. I found that a 47 Ohm resistor in series with the fan will reduce the noice to a whisper and still run the machine nice and cool. So, I had to do some measurements.
A 1 inch miniature fan uses about 60mA at 12V. So running at full tilt, it consumes about 0.72W of power. The minimum setting where it will still start reliably, is about 6V at 50mA, so the power is about 0.3W. So, from that you can see that the power consumption of miniature fans is negligible - almost nothing.
The performance of the little fans vary a lot, but the power consumption of even the worst fan I measured, is still negligible. I am actually typing away on this little machine right now, and I think one fan needs a bigger resitor - still too noisy - need to turn the soldering iron back on...
Excuse me, but please get off my Pennisetum Clandestinum, eh!
I'm one of the brave souls who took apart their MBP and reapplied the thermal paste in reasonable quantities. Problem was, with the stock application heat wasn't transferring properly to the copper tubing from the processors. Unfortunatly, the thermal sensors are on this copper tubing so the problem becomes two-fold. Heat isn't being properly dissipated from the processors, and the computer thinks it is cooler than it really is, so the fans don't kick in when they should. Once the thermal paste was reapplied and everything was put back togother, I noticed my fans would come on more often or even come on full speed at times, which is a noticable sound. As a result, the MBP noticibly cooler to the touch and CoreDuoTemp reports a much cooler cpu.
Similes are like metaphors
It uses IOKit to walk a device tree looking for fan-like things. It enumerates them, and lets you set or read a series of RPM thresholds (min, max, target). The GUI is built on top of the CLI program that does all that.
THIS THING CAN TURN ON A DIME, MACROSSZERO STYLE ALSO FUCK BETA, ~NYORON
They rarely, if at all, are anymore. The only terminology you'll hear used by manufacturers is "notebook", for the burning-lap sterility reasons mentioned.
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