The processor cost of upgrading

December 14, 2009 6:21 AM

Upgrading from OS X 10.4 to 10.6: Does it use more CPU?

I have a Mac Mini 1.66GHz that suffers from overheating problems when placed under stress. I'm looking at upgrading for the extra utilities such as Time Machine and Quicktime Pro, but i am concerned that a newer OS may place more pressure on my weakened computer. Does 10.6 run the computer harder than 10.4?

posted by WhackyparseThis to computers & internet (14 answers total)

I'm not sure what "run the computer harder" means to you, but my install of Snow Leopard right this second is running its typical more than 95% CPU idle, with Safari, LaunchBar, Adium, Terminal, samba, Apache and Hamachi (plus the requisite kexts for that) all operating. See?

Load Avg: 0.05, 0.12, 0.09 CPU usage: 1.28% user, 2.57% sys, 96.13% idle

On a computer with half the processor cycles available, maybe it'd be 90% idle doing all this stuff; that's still not enough load to overheat a machine. I suspect a good chunk of that sys time is that OSX is notoriously inefficient at enumerating process information. top itself was probably half the actual load at the time I was looking.

If by "run the computer harder" you mean does the CPU get railed all the time? No. It probably does that less frequently than Tiger did, since it doesn't have quite as many of the funky mdworker/mds bugs that caused huge long-term spikes in processor load during Spotlight indexing (which is what most people perceived as random CPU load for "no reason").

"a newer OS may place more pressure on my weakened computer"

It's not clear to me what this means. If you're concerned about OSX following the historic Microsoft pattern of lower efficiency and performance in subsequent OS releases, you can be relieved that for most tasks on most hardware, newer releases of OSX tend to be faster and not slower. If you mean something else, you might have to explain more clearly.
posted by majick at 6:38 AM on December 14, 2009

In my anecdotal experience, performance has gotten better with each subsequent release of OSX, but with more ram requirements.
posted by CharlesV42 at 7:06 AM on December 14, 2009

The good news is that your Mac mini has a Core Duo (Yonah) processor rather than the original Core Solo processor. Snow Leopard has been written to take advantage of multi-core processors. Other refinements and optimizations will also help it to run better.

The bad news is the 2GB maximum on this model.

However, your computer should not be overheating. Can you tell us what the common tasks are on this machine? I regularly set up Minis as servers and home entertainment centers and haven't seen any overheating issues.

You should upgrade to Snow Leopard and then optimize the OS for performance for the common tasks.
posted by mrbarrett.com at 7:25 AM on December 14, 2009

However, your computer should not be overheating.

Agreed. Your problem is not the OS.
posted by mkultra at 7:34 AM on December 14, 2009

Have you physically cleaned out your computer? It may simply be full of dust, as it should not be overheating.
posted by odinsdream at 7:40 AM on December 14, 2009

I don't know if you mean overheating like "fan runs all the time" or something worse like "shuts down unexpectedly" I've been running 10.6 on my Macbook Air and have found slightly less of the "fan runs constantly" behavior. I also got a new lap desk which may have helped. Flash seems to be the biggest culprit for Macs and the fan-runs-all-the-time problem. I've also been expermenting with CPU underclocker called Coolbook which can sometimes keep things cool even when I'm dong something CPUintensive. Requires some reasding and understanding to get it working, but you can motnitor your computer's activities in realtime and tweak a little which I found to be a useful thing.
posted by jessamyn at 7:43 AM on December 14, 2009

Yeah, I have a couple of Minis that have been running 24/7 for several years now... but overheating? Not even close, no matter what I do with them.

Something else is wrong.
posted by rokusan at 7:45 AM on December 14, 2009

File down the end a paint scraper, pop the hood and blow out the dust. I do this yearly with my 1st gen PPC Mac Mini.
posted by porn in the woods at 8:49 AM on December 14, 2009

File down the end a paint scraper, pop the hood and blow out the dust. I do this yearly with my 1st gen PPC Mac Mini.

Have you physically cleaned out your computer? It may simply be full of dust, as it should not be overheating.

Ding, ding, ding, ding! We have winners!

My mini (PPC 1.5GHz, Tiger 10.4.11) "died" a week ago. Grey screen would come up and it wouldn't load OS X. I tried all the steps suggested for "grey screen" problems. No dice. So I popped it open to get the HDD out and clone it for the data. The HDD was fine. But I noticed all the vents were closed off with dust. I blew it out, and put it back together. It runs like a champ - in fact the performance improved dramatically (it had been running poorly for months, which I put down to it getting old).

Now, I can't say 100% that this will fix your issues, but I suspect that a "weak" processor is not your problem. Processors don't get "weak" - they are fine or the die, not much in between. Slap on 10.6 if you like, but your problem lies elsewhere. Getting rid of dust is a good start.
posted by VikingSword at 12:05 PM on December 14, 2009

I have taken the computer to a repair shop to have the overheating problem looked at, which helped a bit but did not solve the problem, so dust is not the main culprit. It's usually not a big problem as long as I'm not watching too much flash video, but my worry is that upgrading could make things worse.
posted by WhackyparseThis at 4:06 PM on December 14, 2009

It's usually not a big problem as long as I'm not watching too much flash video, but my worry is that upgrading could make things worse.

I'm going to bet you that upgrading won't hurt, and as a benefit you won't be on Tiger anymore. It might need more RAM, and swap a little bit more, but it should be smarter about CPU and quicker in other regards.

In addition to getting off Tiger, you should install the beta of Flash 10.1. Anandtech looked at it on OS X, and it brought the CPU usage down a lot.
posted by floam at 4:50 PM on December 14, 2009

What exactly do you mean when you say "overheating"? What specifically is happening? I ask because things can cause the fan to kick on, and that would make one assume the mini is overheating even when it really isn't.

Also: where specifically does your mini sit? I tried putting mine in an area without enough ventilation and the fan in my mini kicked on after a while. Even long after the mini had cooled down and was placed in a more suitable open area (on top of my desk), the fan refused to turn off until I zapped the PRAM. Ever since, it's worked like a charm.

I highly doubt the OS is causing your mini to overheat.
posted by 2oh1 at 7:19 PM on December 14, 2009

How much RAM does this Mac Mini have?

If I wanted to overheat a Mini on purpose, I would probably copy files from the DVD drive to the hard disk for hours and hours. Those moving parts generate more heat than "thinking" or watching video.

If the thing is memory-bound, it will swap to disk a lot. If the disk is quite full, it will be swapping to a fragged disk a lot. That could cripple performance and, I suppose, generate heat.

And, yeah, one of those tiny plastic desk fans (from a dollar store) will ventilate the heck out of the area around the Mini if really necessary.

But this all still sounds weird. And I have owned a lot.... a lot... of Macs, including in some hot climates, including the aforementioned Minis that run 24/7.
posted by rokusan at 7:34 PM on December 14, 2009

The overheating problem is something I've grown used to. I have smc fan control display the temperature in the top, so I can see it running at 35 to 40C normally, but quickly ramping up to 50 to 60C when I watch videos. If I let it go on, the sound output dies, then the USB ports start failing, (so I lose my mouse and keyboard) and after that I end up with the kernel panic screen.

I should have taken it back to the store when it was still under warranty, but I was only on dialup then, so the problem only cropped up a couple of times. Now I'm on a decent ADSL plan, so doing things like watching videos online is possible (although dangerous). I installed all the RAM I could when it was new, so that is not an issue. It sits on top of a desk with about 20cm of clear space around it, so there should be plenty of room for ventilation. I will look at getting a cheap wee desk fan though.
posted by WhackyparseThis at 12:10 AM on December 15, 2009