Do I need to reapply thermal compound?

[smodak]

I have a HP m9340f PC with Q6700 processor.
http://h10025.www1.hp.com/ewfr...&dlc=en&lang=en&cc=us#

It was making some kind of excessive fan noise. To investigate I unscrewed the heat-sink (seems to be the stock one) and took it off. I reseated and screwed it back and everything seems to work properly (I have not stressed the PC after that). Do I need to clean and reapply the thermal compound or I am OK?

BTW, the fan noise was from the video card http://h10025.www1.hp.com/ewfr...roduct=3740326&lang=en

I am a bit worried that since I took the heat-sink off, the original thermal compound might be disturbed and the heat won't dissipate efficiently.

If you think I should reapply, what compound should I use? What are the correct steps and precautions?

 

[Schmide]

Yes. Thermal compound is only good for one application. Once it is cured it must be cleaned and replaced.

Although many thermal compounds are marginally greater than others, proper application is more important.

Common white zinc oxide is the cheapest easiest to deal with.

Shin-Etsu, Artic Silver, etc have some advantages.

 

[MyLeftNut]

If your temperatures are okay, you can just leave it. Otherwise, it's only really a problem if it causes temperatures beyond stability or safe operation. The only thing I would think of in why it would affect the heat transfer would be the air bubbles introduced when you put the heatsink back on without reapplying fresh paste.

 

[smodak]

Thanks. What would be safe idling and load temps of a Q6700? I am using speedfan to measure. I need to replace the video card before I can fully test it.

 

[Schmide]

Use Core Temp

>70 load

 

[smodak]

thanks. that is in Celsius right?

 

[Bill Brasky]

Yes, in Celsius.

 

[ScorcherDarkly]

Thermal compound is only supposed to be used for filling in the gaps where the metal from the heatsink and the metal from the processor aren't flush. The TIM is much more conductive of heat than air, so you use the TIM to fill the gaps where air would be normally to further reduce temps. Applying some TIM again may improve your temps, but if you've already got it on there and everything is running cool, you probably don't need to mess with it.