Since I installed 4 GB of RAM in my Late 2008 Unibody MacBook,
I've found I can go for very long periods of time without rebooting to
clear the memory heap, without noticing a substantial slowdown in
performance.
For example, the other day I realized that I couldn't remember the
last time I restarted my computer. I'm virtually certain it had been
over a month earlier, possibly even six weeks or two months.
Running Hot
However, I watch Temperature Monitor like a hawk, and I had begun
noticing that the MacBook was tending to run a lot hotter than usual,
the processor temperature often climbing into the low 80s Celsius,
while I had previously found the typical range to be in the high 60s,
depending somewhat on ambient environmental temperature. While we've
been having warmer than normal (by a lot) temperatures here in Nova
Scotia for most of the winter and spring, the 'Book was still running
hotter than I recalled from last summer.
I usually have a lot of applications running - four browsers,
usually two or three image editing applications, a couple of text
editors, email software, and several utilities. My suspicion had been
that browsers are one of the worst heat generating offenders.
I really detest fan noise - even with the relatively unobtrusive
little fan in the Unibody MacBook - and I also prefer to keep my
computers running as cool as is consistent with doing the job I need to
do with them.
System Maintenance
I decided that since I'd downloaded (but not yet installed) the
Apple Security Update 2010-002 for Mac OS X 10.5.8, a
kill-two-birds-with-one-stone reboot would be in order - and hopefully
help cool things down. Actually three birds. I like to run a set of
system maintenance routines - Repair Permissions; run the daily,
weekly, and monthly cron scripts (I don't keep my computer up and
running all night for them to run automatically at the traditional
times, although I think I heard somewhere that the system will get
around to it sometime regardless); and various cache dumps at least
once a month or at reboot time, if the interval is longer than that, so
I was overdue.
My favorite tool for this job is freeware OnyX's
convenient "Automation" routine, which lets you custom tailor your
maintenance runs using checkboxes and then just let it do its stuff,
but there are a dozen or more other system maintenance utilities that
will get you there as well.
Apps and Temperature
OnyX requires that all other applications be shut down while it
performs maintenance, and I noted that without the browsers and
Thunderbird (I'd been using version 3.1b Lanekai lately) up and
running, the processor temperature almost immediately dropped by
10° to 14° C. This intrigued me enough to try closing and
starting up the browsers and Thunderbird separately. The main browser
culprits turned out to be Chrome and FireFox, which spiked the
processor temperature from 57-58° C to 64-66° C and 68°
respectively when idling. With just Opera 10.5.0 running and the
others, along with Thunderbird, shut down, things cooled again to a
very tolerable (and fan noise-free) 57-61°. Starting up Chrome
(version 5.0.371.0) pushed the temp up to 64-66°, and adding
Firefox (version 3.6.3) boosted the temp to 66-68°.
Starting up Thunderbird 3.1b1, with Opera the only browser running,
drove the temp up to 66°, but I discovered that running the T-Bird
3.0.3 final version dropped it back to a more respectable 59°, so
it appears that the Mozilla.org folks have some cleaning-up and
optimizing to do with the T-Bird version 3.1 code. Running T-Bird 3.0.3
and Firefox 3.6.3 simultaneously didn't raise the temp further,
remaining in the 67-68° range when idling or under light load, such
as typing.
Cooler After Restart
The maintenance run took maybe 20 minutes, and the Security Update
install considerably less than that. All went smoothly, and upon
rebooting twice (for OnyX and then the system update), I noted that
even with the browsers relaunched, I was now getting processor
temperatures in the 62° to 74° range upon restart - better than
the low 80s it had been running often during the past several weeks.
Shifting to text entry (browsers still open but idling), the temp
dropped into and stayed in the mid-high 50s and low 60s, and for the
most part, processor temp stayed in the 60s, substantially lower than
it had been prior to the maintenance routines and Security Update
install - the effect of the latter, if any, on temperature being an
imponderable.
Quietness and serenity were restored, and my MacBook is running
cooler than it had been, which is great.
I will be interested to see how this issue is affected by installing
Snow Leopard, which I
finally bought a copy of but haven't gotten around to installing yet.
If it helps cool things down a few notches, I'll consider the upgrade
well worth it, but I'm still waiting impatiently for a Snow Leopard
compatible version of WindowShade X, of which there is as yet no sign,
and there haven't been any progress updates on the Unsanity Software
news blog for some time either, which has me increasingly
concerned.
Anyway, if your laptop is getting a bit sultry and you haven't
rebooted or done any system maintenance for a while, it's well worth
giving it a shot, as well as keeping an eye on which browser and email
software you're running.
