Welcome to the MacNN Forums.

stuffedmonkey · Mar 25, 2003, 08:48 AM

I was reading a few PC mags (hey, they have good hardware info... so shoot me..

) and I noticed all of them swear that Artic Silver 3 thermal paste rules. So as an experement I got a tube off ebay for 4 dollars...

I have an AGP graphics G4 450 - and at 100% usage the CPU temp was always at 104F. I pulled off the heatsink - there was Nothing between the cpu and the heat sink itself! I put an eeensy bit of Artic Silver 3 between the sink and the CPU and put the thing back together. Now I can't get the thing any hotter then 96F! Why such a big deal? Well if you are overclocking 8 degrees can be huge.... And even if you don't overclock - running cooler means longer CPU life and less chance of burnout.

A few warnings - Do Not pull off your processor unless you know what you are doing!!!! Static shock can ruin the thing. And be careful not to put too much paste on the cpu! more is not better!

Another disclaimer - I am not a shill for any thermal paste company. I actually work as a computer repair tech.....

I used Thermoindock for my CPU temp results. I know it's not 100% accurate, but it does give me consistant results, and it's freeware.

D'Espice · Mar 25, 2003, 09:04 AM

Dude, 96�F is pretty hot. I've had a G4/350 CPU in my Sawtooth PowerMac, it was always around 85�F at full load.

Few weeks ago, I got a free G4/450 CPU and after removing the heatsink in order to swap the CPU I noticed, that there was nothing between the CPU and the heatsink. I did pretty much what you did, I put an eeensy bit of Arctic Silver between the heatsink and the CPU (due to the fact that I also have PCs, Arctic Silver is one of the things I'm never short of) and now I can't get it hotter than 82�F at full load and around 70�F at part load. And since the huge fan in my Sawtooth is temperature controlled, my Mac seems less noisy now.

By the way, room temperature has a very high impact on CPU temperature, mine's 74�F right now.

mbryda · Mar 25, 2003, 11:17 AM

As long as it's within specs for the CPU, the heat is nothing to worry about (unless you OC).... In the end the machine will get too slow to do work before the CPU dies because of the difference between 100 degrees adn 80.

Turbocharger · Mar 25, 2003, 01:35 PM

Originally posted by mbryda:
As long as it's within specs for the CPU, the heat is nothing to worry about (unless you OC).... In the end the machine will get too slow to do work before the CPU dies because of the difference between 100 degrees adn 80.

Maybe it's nothing for YOU to worry about, btu the cooler a CPU runs, the better, even if it's within specs. To be honest, I'm surprised that Apple does not use a heatsink compound as standard procedure during manufacture. I've already lost one of my two CPU'S (which was replaced under warranty) and it was a real pain, so every little bit helps. Using thermal paste certainly won't hurt...

Eug · Mar 25, 2003, 02:29 PM

Yeah, weird that they don't use anything. I would have suggested a thermal pad. Nowhere near as good as thermal paste, but clean and easy, and significantly better than using nothing.

(I use the original Artic Silver myself for my PCs.)

G4ME · Mar 25, 2003, 04:26 PM

how much should you apply? just enough to cover the proc? with a thin layer

D'Espice · Mar 25, 2003, 04:50 PM

Originally posted by G4ME:
how much should you apply? just enough to cover the proc? with a thin layer

Not more than a drop in the middle of the CPU.

Turbocharger · Mar 25, 2003, 04:53 PM

Originally posted by G4ME:
how much should you apply? just enough to cover the proc? with a thin layer

Here's a link for instructions on using Arctic Silver.

Link:

http://www.arcticsilver.com/arctic_s...structions.htm

mbryda · Mar 25, 2003, 05:19 PM

Originally posted by Turbocharger:
Maybe it's nothing for YOU to worry about, btu the cooler a CPU runs, the better, even if it's within specs. To be honest, I'm surprised that Apple does not use a heatsink compound as standard procedure during manufacture. I've already lost one of my two CPU'S (which was replaced under warranty) and it was a real pain, so every little bit helps. Using thermal paste certainly won't hurt...

If the CPU is good it won't matter what the temperature is as long it's within the specs.

Think about it this way - you can take a laptop out in the heat of 100 degrees and it will work perfectly fine. As soon as you fire it up, it will be at 100 degrees because of the ambient temp. It will not suffer any heat related things as long as it's within the specs of the CPU. CPU's (Morotolas in marticular) operate in some VERY harsh environments (telco equpment, cars [VERY brutal], heat, cold, etc. and they just chug along.

Just because you lost 1 CPU does not mean it was because of heat. It could have been a defective unit from the day it was made and just waiting to go regardless of the heat issue. You probably could have stuck that CPU in a meat locker and it still would have failed. I've seen CPUs be junk from the first power on and others that go after a couple minutes. Sometimes its the luck of the draw.

If you want to go through the trouble and expense of using extra cooling, that's fine. However, to the computer it won't matter if it's operating at 80 or 100 degrees, especially in the short lifespans of a consumer computer.

CheesePuff · Mar 25, 2003, 05:41 PM

96?_is not hot... 130? is. Mine usually runs at 115? or so.

Eug · Mar 25, 2003, 06:57 PM

Originally posted by mbryda:
If the CPU is good it won't matter what the temperature is as long it's within the specs.

It depends on what those specs are. Sure if the max is supposed to be 120, running 40 or 60 won't matter, but it's a big deal going from 90 to 110. A little added heat (eg. hot summer day, broken case fan) can cause problems.

mbryda · Mar 25, 2003, 07:47 PM

Originally posted by Eug:
It depends on what those specs are. Sure if the max is supposed to be 120, running 40 or 60 won't matter, but it's a big deal going from 90 to 110. A little added heat (eg. hot summer day, broken case fan) can cause problems.

True, but most CPU's will shut down when they overheat and most types of problems (CPU Fan stopping, case fan, etc) will not cause issues with the CPU. In 10 years of seeing various CPU fan failures, I've never seen one that took the CPU from a simple fan stopping. I've seen AMD 486's have fans stop for like 2 months before the owner realized it. Pop in a new fan and the thing keeps on running. Same with the K62/350. (both were my parent's machines) Also had a friend's Athlon XP 1800+ overheating regularly for a month or so before we found out it was a slow running power supply fan. That was a year ago....No problems since.

The only time heat can become an extreme issue is if a heatsink falls off (see Tom's sensationalistic journalism for what can happen). However, in 10 years of being a tech in the PC business I have yet to see that happen. Ever. Usually it's a simple fan stoppage.

sonoronos · Mar 25, 2003, 08:19 PM

Lower temperatures will always result in higher CPU reliability in MTBF. Even a difference of 1 degree fahrenheit will make a difference. All CPUs are manufactured using the same processes and while some are designed to tolerate higher temperatures, their life in such environments are drastically reduced over those that operate at lower temperatures.

I don't know about you, but these CPUs are expensive

The way Apple is moving with their CPUs you might not even get a replacement that'll fit your mobo when it burns out tho!!

reverb · Mar 25, 2003, 08:49 PM

Dude, 96�F is pretty hot.

96F is not at all hot for any G3 or G4 processor. Actually, it would be on the low side in most applications (with normal ambient temps).

JB72 · Mar 26, 2003, 01:52 AM

thermal paste=good.

I'll be adding some sound dampener to my MDD eventually, so anywhere I can compensate by reducing a few degrees is well appreciated. Especially if I start seeing OC in my future.

bartman00 · Mar 26, 2003, 05:35 AM

I have a G4-450 sawtooth upgraded with a Sonnet duet and it did have a had a thermal pad on the apple heat sink. It was a graphite thermal pad and is more than adiquate to keep the 450 cool. I also watch the apple tech where I used to work take apart other sawtooth's and they all had the exact same thermal pad. Are you sure your's diden't have a graphite thermal pad?

And if you got some Artic Silver off ebay for $4 I'd be willing to bet it's not real Artic Silver, there have been alot of people selling fake AS on ebay. So much so that AS actually has a part of there www site devoted to spotting fake AS.

Bart

mbryda · Mar 26, 2003, 08:10 AM

Originally posted by sonoronos:
Lower temperatures will always result in higher CPU reliability in MTBF. Even a difference of 1 degree fahrenheit will make a difference. All CPUs are manufactured using the same processes and while some are designed to tolerate higher temperatures, their life in such environments are drastically reduced over those that operate at lower temperatures.

Does it really matter? The MTBF rating is usually well over 200k hours - or 22 years. Even if you shorten it in half, it's 11 years. How many people keep their computers 11 years? Heat can kill semiconductors, but it's not as big of a deal as some would have you think.

stuffedmonkey · Mar 27, 2003, 08:33 AM

bartman00 - It is indeed Artic Silver - I had actually checked thier anti fraud site first. The fake stuff looks WAY different. You can get it online for 6$, so ebay for 4$ is not that bizarre a deal (I got the smallest size - which should be good for several computers....) It's not like i'm buying a 5$ Rolex

But to the others, he is right - you should make sure you are buying from someone reputable. there is a lot of fake stuff being sold....

exa · Mar 28, 2003, 01:25 PM

Not sure the room temperature thing is accurate, because I've had my Beige G3 report temperatures of 50-60F when the room temperature was in the 70s.

Aren't consumer processors rated up to 160F anyway?

sideus · Jun 23, 2003, 03:04 PM

Bought 3grams of Arctic Silver 3 (it is genuine) for my MDD Dual 867MHz. Running iTunes and Quicktime movies while browsing. The temp is stuck at 52 Celcius. Very cool!