As I slowly crawl my way out of a case of “walking pneumonia” that has lasted for over five weeks now, and while I’m still not up to anything that requires much energy, mental or physical, let me report on the health of my MacBook Pro system, which has been occasionally running a fever far, far higher than the low grade ones I’ve been experiencing from time to time. Beyond entertaining the (probably few) who enjoy accounts of unsolved computer problems, I’m hoping that, in case others have encountered similar unexplained behavior, this report might provide data to help someone figure out what the likely cause of the problem is.
Back in March in a post called Vista on My MacBook Pro is Hot—Boiling Hot!, I reported on the high temperatures (up to 100° C or 212° F, the boiling point of water) I’d observed while running graphics-intensive software under Windows Vista installed on a Boot Camp partition on my first generation MacBook Pro. Since not a day goes by without a few visitors arriving at this blog due to Google searches on terms such as “macbook pro runs hot in vista,” I’ve concluded that the high temperature under Vista must be something that has caused concern to a lot of people. I have no way of knowing if this is mainly Apple’s, Intel’s, or Microsoft’s fault, though I suspect it is Apple’s, since Vista’s operating temperature would naturally have a much lower priority for Apple.
I’ve recently observed temperatures under Mac OS 10.5.5 that make the Vista temperatures seem mild in comparison, however. The first new record-setting temperature occurred for no apparent reason several weeks ago. I had given Microsoft Office 2004 Update the go-ahead to install the latest update of Mac Office 2004 in the background while I went about my business. After a while I noticed that the fans were revving up higher and higher. I checked the temperature with the iStat Pro widget and saw that the MacBook Pro was hot all right, having reached 104° C with no sign of starting to cool. I realized that Microsoft Update was still open even though the update had been completed some time ago. Could that be the source of the heating?
Sure enough, when I quit the Update program, the system started to cool right away. It may have been a coincidence, but it was too dramatic not to convince me that somehow Microsoft Update had put the system into a a funny state that made it run hotter and hotter. Since this had never happened before, and since it seemed to be associated with the Update software, which had run numerous times before, I can only guess that the problem has to do with the Mac OS version I was running under, which at that time could have been as early as 10.5.4.
Perhaps running the Update software had disabled the fan response to temperature rise and then, upon completion of the update, the fans had kicked in and would have brought the temperature down anyway. In that case the temperature drop when I quit the Update program would have been a coincidence. The fans were definitely running at high speed by the time I quit Office 2004 Update, but not having checked the temperature earlier, I can’t say that it hadn’t actually been higher than the 104° C I observed just before I quit the Update. It’s hard to get rid of that gut feeling that the Update software was somehow causing the system to heat up though.
A few weeks ago, some time after that record temperature, while I was definitely running OS 10.5.5, a much more dramatic and disconcerting heat spike occurred. I was online at Guy Kawasaki’s blog, scrolling down a page (probably in Safari, but possibly Firefox) which contained many photos that Guy had taken. These were all still photos, not videos. I wasn’t pausing to look at most of them, just scrolling past them on my way to an earlier post lower down. I noticed the fans were running at a high speed. I brought up iStat just in time to see the temperature had reached 121° C (250° F) before the computer shut down, presumably due to overheating. As before, I have no way of knowing whether the temperature spike was the result of scrolling past many images, some intermittent, randomly occurring, hardware problem, or something unrelated to hardware or what I was doing on the computer at the time.
Then on election night, when I was halfway through watching an online video of John McCain’s concession speech, the MacBook Pro suddenly shut down again. I didn’t have a chance to observe the temperature before this happened, so I don’t know if it was a high temperature shutdown. Watching videos invariably causes the fans to speed up, so that wouldn’t have caught my attention. I had experienced one sudden shutdown before the one definitely associated with high temperature, and I had not considered high temperature as a likely cause then, not having observed the very high temperatures before. Now I have to suspect overheating as the cause of that earlier shutdown.
I’m trying to keep a closer eye on temperature now. I worry that having the temperature become high enough to cause a shutdown will eat into the expected lifetime of my machine. I’d be interested in hearing from anyone that has seen similarly high temperatures. Have others had shutdowns due to high temperatures? Use the link toward the upper right to send me an email. I’m weakly hoping it’s something that Apple will quietly fix in the 10.5.6 version. Until then, that 121° C reading is just one more way OS X soundly beats Vista.