Phase-change pad vs grease...

[Mini-Me]

Hi all.
:)

I have kinda lost my faith in the phase-change pads supplied with new CPU/heatsink/fan retail boxes.

More often then not, the pad does not seem to be anywhere as efficient at getting the heat away from the CPU core then gold old silver grease.

It's summer(kind of! :p ) over here at the moment, and many high-spec machines cook themselves at this time of year, due to the relitively high ambient temperature.

All the following comments with respect to a 32'C ambient daytime temperature.

A computer that came to me today, was running a 47'C core temp when simply looking at the hardware monitor in the system BIOS.
...a tad warm...

BIOS reports all voltages fine, and CPU fan running around 4200RPM.

I asked about the machine, and found that the CPU had been upgraded from the original Duron 1200 to the now Athlon XP 2800+.
The upgrade was done at home, via a retail CPU/heatsink/fan pack.

The heatsink was mounted well, and no problems there, and when removed, there was a nice depression in the thermal pad, indicating contact with the CPU core.

When pulled off the core, the thermal pad fractured - part stayed stuck to the core, and the rest remained stuck on the heatsink.

The thermal pad was flakey and dry to the touch.
This seems to be the norm whenever I remove a heatsink from a core that has had this pad thing fitted to it's cooling method. I cleaned the heatsink with a putty-knife, and cleaned it down with isopropyl.

Having cleaned the surface of the core with isopropyl carefully, so no trace of the old pad was there, I put a thin smear of silver grease on the core, and then replaced the heatsink.

After powerup, and in hardware monitor in BIOS, with the same 32'C ambient temperature, the idle temperature of the core is now a much more happy 41'C.

Any thoughts?

As I said: This is not the 1st time I have come across what appears to be dried out thermal pads, which actually seem to have quite a bad efficency...

From now on, I am gonna scrape those phase-change pads off right at the beginning with a new CPU, and install the heatsink using silver grease.


MM.

[saphalline]

You do indeed live in a much warmer climate than most of us, but keep in mind that altering the stock retail cooling method in any way can be construed as voiding the warranty according to Intel and AMD. And the voiding of the warranty is at their discretion. Sometimes they'll honor a warranty when thermal grease is used, but most often not if the application was improper in any way and regardless if it directly caused harm to the CPU.

With that said, it seems that thermal grease works a lot better in your region of the world because of the high ambient temps. Whenever changing from a stock retail CPU cooling solution, it's always best to warn the person about the warranty being voided, whether that means altering the stock HSF unit or going for an OEM CPU. When viewing the numbers (especially in your area I suspect) a surprisingly large number of people are willing to take the "risk" in order to get better cooling. This can only translate into greater stability for them, and an increased lifespan for the CPU. Still, some people prefer the peace of mind that warrantees give them. Don't ever alter anything unless you get permission!

Oh, by the way, those pads are called "thermal pads" and involve no phase changing at all. They exist in an amorphously fluid state at all times, much like glass. Phase-change cooling techniques are most often used in PC's for extreme OC'ing and involve a liquid with a very low boiling temp & pressure (most often a covalently-bonded water-soluble liquid not entirely unlike the cooling liquids used in automobiles). Phase-change cooling for PC's is very toxic, very messy, and very expensive.

[Mini-Me]

Sorry - got my Phase-change confused with my thermal pads - thanks for the correction.

I also note your comments about voiding the warranty - this is a very good point, and one I should have made in my original post, so thanks for that!
:p

The CPU I dealt with yesterday had been put in about 8 months ago, so still under warranty. If there are any problems with warranty, I will use my company name to back the reason for the change. If the change was done by a company who services PC's(as I do as a part-line), you generally can get away with voiding the warranty, so long as whatever you do, did not harm or shorten the life of the product. You can't get this kind of leeway when done privately at home.

Does anyone else here have "Overheating" issues with the use of the stock thermal pads?

...I see it all the time here...

I'm just wondering if perhaps they use cheap nasty material in the thermal pads, cos it does the job "OK".
I suppose the one major thing in support of the thermal pads, is the non-mess way in which they are installed - no goo everywhere and on your fingers!
:D
(note: I don't get heatsink goo on my fingers and all over the place, but some people do! they practically drown the device, and when the heatsink is put on, all the goo oozes out the edge between the device and the heatsink!)


MM.

[paul_]

arctic silver 5 :cool: