Torrid Notebooks - How Hot Is Too Hot?
Wednesday, August 8, 2007
by Charles W. Moore
It’s high summer (at last!) here in Nova Scotia, Canada, where I live. August is absolutely my favorite month of the year here, with September often pretty wonderful as well. July can go either way, but too often it’s wet, humid and not quite as warm as one would prefer. August and September are our most dependable months here.
Traditional Oriental philosophy recognizes five seasons, adding “Late Summer” to the four familiar to us in Western culture. I think they’re on to something , and the five season model certainly works here in Atlantic Canada with our bucolic Augusts and typically mild, pleasant autumns.
It’s also of course the hottest time of the year here, with temperatures typically climbing into the 80s F. and not uncommonly the 90s, which would just be moderately warm weather in, say, the southern U.S., but it’s hot by East Coast Canadian standards.
Sultry summer weather also taxes the cooling capacity of notebook computers, and the cooling fans in my 1.33 GHz G4 PowerBook have been getting a workout for the past few weeks since the summer weather arrived, and seemingly quite a bit more than in similar weather last summer when I had OS 10/4/6 installed. This summer it’s OS 10.4.10, and my impression was that fan running frequency and intensity bumped up a notch or two after I installed the OS 10.4.9 update even. back in the chilly part of the year.
The PowerBook is mostly used sitting on a Road Tools Podium CoolPad, and interestingly, the surface of its aluminum case doesn’t feel hot, or even more than lukewarm most of the time, not nearly as warm as my G3 iBook’s tactile surfaces get, which indicates that the large expanse of metal case surface does an efficient job of dissipating heat through passive radiation, but the processor itself gets quite torrid. According to the Temperature Monitor utility, the fan cuts in when the processor bottomside under load reaches about 58.5° C, and I’ve never seen it register more than 60°, which is more than hot enough by my lights, but relatively tepid compared with temperatures being reported with the Intel Core Duo MacBooks and MacBook Pros.
The online Intel Mac Temperature Database covers MacBook Pro and MacBook models up to 2.16 GHz, with most running in the 75° - 90° C range under load in ambient temperatures of 20° to 23° C (68° - 72° F) That’s pretty hot, although reportedly the newest “Santa Rosa” based MacBook Pros run somewhat cooler than earlier Core Duo and Core 2 Duo machines. In the data, variables including the amount of RAM installed, the capacity and running RPM of hard drives, and the operating system version are also noted and accounted for as contributing to internal heat buildup.
There have been many articles posted on the Mac Web suggesting possible causes, cures and workarounds for hot-running MacIntel ‘Books, some blaming excessive application of thermal grease on the processor during manufacture, others with software hacks that, uh, make those cacophonous internal cooling fans run faster and/or more frequently (http://www.macinstruct.com/node/198 such as this one posted by MacInstruct this week), although the latter is definitely not an attractive “fix” to my way of thinking.
The heat escalation that was introduced with Apple’s switch to Intel processors was one of the reasons Apple stopped referring to its portable computer models as “laptops” and substituted “notebook.” Many users report that these machines, especially the early Core Duo models, get uncomfortably hot (as one commentator recently put it: “a wrist rest you could fry an egg on”) and would not be something you would want to have on your unprotected lap, which kind of takes a lot of the fun and versatility out of portable computing.
Apple affirms that “the bottom surface and some areas between the keyboard and LCD hinge of your Apple notebook computer can become hot after extended periods of use. This is normal operating behavior. With processor and bus speeds in portable computers often matching, if not exceeding, those of desktop systems, increased operating temperatures in portable computing products are common throughout the industry.
“For prolonged use, place your iBook, PowerBook, MacBook or MacBook Pro on a flat stable surface. Do not leave the bottom of the computer in contact with your lap or any surface of your body for extended periods. Prolonged contact with your body could cause discomfort and potentially a burn.”
They go on to suggest that “When using your portable computer, place it on a hard surface, such as a desktop or a tray. A hard surface allows air to flow under the computer to dissipate heat.” Good news for laptop desk makers. Maybe Apple should just bundle laptop desks with each Intel ‘Book sold.
Low End Mac’s Andrew J. Fishkin reports that his MacBook has hit 85° C and typically hovers around 77° C, while the highest temperature he ever noted with his G4 12-inch PowerBook was 68° C, which is a lot hotter than any of my ‘Books has ever gotten, but Andrew lives in California. I guess owners of recent Apple laptops who reside in warm climates are obliged to live with a serenade of howling cooling fans most of the time, a prospect which does not enchant me in the slightest. I guess there is an upside after all to the sort of whether we get here in Atlantic Canada 10 months of the year.
Incidentally, I should note that the fans in my G4 upgraded 550 MHz Pismo PowerBook and my 700 MHz G3 iBook, both with 640 MB of RAM and running OS 10.4.9 have not come on even once this summer so far, and if I recall accurately they didn’t last summer either - one of the advantages of using obsolete ‘Books.
I absolutely detest fan racket, and being afflicted with multiple chemical sensitivity as I am, the fact that hot plastics off-gas chemical vapors more profusely is problematical well.
My first PowerBook, a 5300, would barely get warm to the touch - just enough to be a comfort to your left hand on chilly Nova Scotia days. With its anemic 100 MHz Motorola 603e processor, to the old 5300 just didn’t have much heat-generating capacity or any necessity for a noisy cooling fan. Unfortunately, it didn’t have a whole lot of computing power either, and my son’s 25 MHz 68LC040 PowerBook 520 could outperform it in certain contexts. The 520 didn’t get very warm either.
The first Mac laptop model with a thermostatically-activated internal cooling fan was the PowerBook 3400c, which also had a 603e chip, but a hotter one both literally and figuratively. The 3400’s fan didn’t cut him very often, but was there on standby if required.
The PowerBook G3 Series 233 MHz that I replaced my 5300 with had a fan, but it never spun up during my first three and one half years of ownership, until just a few days before the G3 processor burned out on a hot midsummer day in - you guessed it - August, 2002. Since I replaced the processor by simply swapping in a scrounged daughtercard, the fan has stayed resolutely silent, summer and winter, and the big old WallStreet, which my wife still uses daily, barely gets warmer to the touch then the older 5300 did.
The same went for my PowerBook Pismo with its original 500 MHz G3 processor as well, which ran cooler than the WallStreet, thanks in part to a more sophisticated internal cooling system.
My 700 MHz iBook G3 runs significantly higher than any of my older PowerBooks. Its case feels noticeably warm or even borderline hot sometimes, although it’s internal fan never spun up during the first two and one half years I owned it, again until a hot August day after I had upgraded OS 10.4 Tiger, after which the fan did cut in during really hot weather, albeit not very often.
One of the aspects of using laptop (sorry - notebook) computers that has traditionally appealed to me has been their relative silence. During the first ten months I owned the PowerBook 5300, during which I had no Internet access, I used to run most of the time from a RAM disk, which allowed me to keep the hard drive spun down any eliminate even that noise distraction. One of the things that would theoretically appeal to me about flash-memory-based laptops is the absence of hard drives grinding away in the background, but with the contemporaneous reality of cooling fan running most of the time anyway in order to keep the CPU from self- immolating, the peace of NAND would be largely canceled out.
Notwithstanding my own WallStreet’s processor meltdown, apprehensions that were widely voiced back in 1988 when the G3 Series PowerBooks debuted about potentially shortened service life due to the G3 processor’s higher operating temperatures seem a bit quaint now, being as the WallStreets were cool runners compared with the MacIntels and even the faster PowerPC G4s, and the G3 Series turned out to be one of the more reliable, long-lived and dependable PowerBook models ever.
Nevertheless, one must presume that there are physics limits that obtain at some point, and excessive heat can’t be good for electronic components. You do have to wonder how long these blistering hot Intel-powered ‘Books are going to last, running at Internal temperatures high enough to fry eggs. Intel rates the Core Duo for service up to 100° C, so the MacBooks’ processors are well within tolerance, but what about the other internal components?
It certainly gives one pause. The relentless fan cycling is just about the only thing I really dislike about my 17-inch PowerBook, but I dislike that a lot. Doesn’t augur well for my level of content with a MacBook or MacBook Pro, and I have to say it’s a great relief to sit down with the Pismo or iBook knowing that I’m not going to be subjected to fan cacophony with a few minutes of running time, and these machines can be still used comfortably as actual, literal laptop computers.
However, curmudgeonly impatience with noise pollution aside, there is a more do objective and potentially hazardous issue in play here as well. There have also been some highly publicized incidents of laptop computers spontaneously catching fire, notably an Apple iBook in the US midwest, and a Dell laptop at a trade show in Japan. There were no injuries in either case, but there was some property damage (aside from the computers themselves), and one shudders at the thought of something like that occurring aboard an aircraft in flight.
Last year, the Toronto Globe and Mail’s Alex Dobrota reported that there have been as many as 43 laptop fires reported in the United States since 2001, according to statistics compiled by the U.S. Consumer Product Safety Commission. Dobrota cites Linda Nazar, a chemistry professor at the University of Waterloo in Ontario explaining that the lithium ion batteries that power most laptops produce electricity through a chemical reaction that releases oxygen which can react with organic solvents in the battery’s plastic parts to produce heat that can melt the battery’s membrane, and possibly lead to the laptop catching fire. Not a happy thought.
It seems that processor performance is running up against the laws of physics that dictate that if you put a heat-generating object inside a small, inefficiently ventilated space, it’s going to get hotter. The heat problem with today’s portable computers is a combination of faster processor speeds, fashion’s demand for thin form factors, more RAM, faster, higher-capacity hard drives, and operating systems and other software that place ever greater demand on processor power. All that speed and enhanced functionality is great to have, but not if it burns your house down or worse.
Over the OS X era, I have daydreamed from time to time about how much more speedy and efficient OS X might be with a bare-bones simple GUI like System 6 had. Personally, I would happily live without the eye candy and gimmicky stuff if that would mean snappy performance with more modest power that didn’t require fan-forced cooling, and I could be content with thicker case profiles as well.
Or perhaps there will be a technology breakthrough that will result in quiet laptops than can officially be called “laptops” again without courting litigation from someone whose thighs get roasted. Here’s hoping.
Note: Letters to PowerBook Mystique Mailbag may or may not be published at the editor's discretion. Correspondents' email addresses will NOT be published unless the correspondent specifically requests publication. Letters may be edited for length and/or context.
Opinions expressed in postings to PowerBook Mystique MailBag are owned by the respective correspondents and not necessarily shared or endorsed by the Editor and/or PowerBook Central management.
If you would prefer that your message not appear in PowerBook Mystique Mailbag, we would still like to hear from you. Just clearly mark your message "NOT FOR PUBLICATION," and it will not be published.
CM