Lapping

[rivercom9]

I have an AMD K6-2. I recently lapped my heatsink, but I did not notice any difference in CPU temp. Sould I lap the heat plate of the CPU or is it not worth the trouble? I want as much cooling on it as possible, but only using air. My current hsf is one taken from a boxed 1.4 Gig Athlon. Would there be an increase in cooling if I did lap the heatplate on my K6-2?

[Koooler King]

From my experience, lapping is only useful if the base of the heat sink is way out of flat (then it probably needs more work than just simple lapping) or if has a very rough surface finish (if you can see machining swirl marks), then lapping may help. If the base is so rough as to have grooves or swirl marks, use wet-dry auto sandpaper. Start with something like 320 grit, wetted and placed on top of a flat surface with a cushion (corrugated cardboard works well). Use 240 grit only if the 320 grit is too fine to clean up the base. Gradually work to finer grit, 400 then 600. The important thing is to have it clean-up in the middle just over the footprint of the cpu chip. Going finer than #600 is probably not needed. Also, I have found 3M branded sandpaper to work better and smoother than generic "Home Depot" type sandpaper of the same grade ... you get what you pay for!

Arctic Silver grease or equivalent will fill in the voids perfectly if you have a reasonably smooth and flat heat sink base. I have heard that finer polishing may actually be a detriment. To support that, I have also tried #800, 1200, 1500 grit paper and then super polished heat sink bases beyond the finish from #600 paper. It was pretty and shiny, but I never could measure any further improvement with that level of attention. Good Luck!

Koooler King

PS: Very useful tip ... knock off the corners of the bottom of the heat sink with a file prior to lapping to avoid tearing the sandpaper.

[Yodums]

What was your method exactly?

I just finished lapping my slot heatsink(serious pain to lap) and it took 2 hours.

I was on 220 grit for 1 hour and 15mins to finally sand down the whole layer.

Lapping the plate won't make a difference as they're fairly flat.

Make sure that you did it all correctly and went through the sandpapers above your regular grit all with the same time and a little longer finish time.

Make sure when using your first grit(should either be 220 or 400) that you don't move on to the next grit without sanding down everything.

Make sure before you put the heatsink on that you clean it with alcohol to clean off some left over metal, and make sure there you don't touch it.

[rivercom9]

The base of the stock Athlon hsf was pretty smooth, but not flat. I began with 800 grit until I had it completely flat. I then moved to 1000 grit, then to 1500. After the 1500, I proceeded to polish the base of the hs which was flatter than before with Mother's Mag and Aluminum polish. It had a mirror like finish when I was through polishing it. I then cleaned the base of the hs with alcohol in order to remove remnants of the polish. I did this several times and then applied Cooler Master thermal compound to both the hs and the CPU. I had used Radio Shack thermal compund before lapping the hs. Could this have made a difference? Is the Radio Shack stuff better than the Cooler Master stuff? Why havent I seen any improvements in my cpu temps?

[dreadlord79]

Was the paste a white-ish color? If so, it is not as good as using a product like Arctic Silver II or Arctic Alumina paste which have been tested to give better results that the others. The reason is because the AC II and Alumina have very small particles of silver in them which conducts heat better than most silicon based products such as the ones you mentioned. One draw back of AC II or Alumina is that since they do have small particles of metal in them, this makes them able to transmit electricity better, some times resulting in shorts. With the proper percasions, this can be avoided. Hope this helps. :)

[rivercom9]

Where can I find good deals on Arctic Silver 2?

[rivercom9]

So which thermal compound is better? The Radio Shack or the Cooler Master (High Performance)?

[Billvill]

Ohhhh I am sorry, I thought this was the Lap Dancing Room .

To answer your question I don't think it is worth the effort to work the chip and heatsink anymore than you have . I would make sure you have a good thermal compound such as artic silver avaliable here (www.pcnut.com) between the chip and the heatsink.

Billy

[dreadlord79]

Rivercom9, I've seen AS II any where from $8 to $12. Just look around a little and if you need something for a cooling project, just go to a site that has the AS II and the part you need so the shipping and handling doesn't eat you alive.

*edit* I personally like Crazy PC or HeatSink Factory both of which you can find the links to in the banners on the front page.

[rivercom9]

Thanks for all the replys. I guess I can save some time by not lapping the CPU. Now to figure out what to do now with my spare time. Hmmm....Maybe I can go find a job.