[Joshuashawharvey]

I was giving my computer a good cleanout, blowing all of the dust out and giving it a new layer of thermal paste, when I noticed how rough the surface of my heatsink was. So I decided to give lapping a go.

For those who don't know what lapping is, lapping is using very fine grit wet and dry paper to smooth out the base of the heatsink and/or CPU as some extreme enthusiasts like to do, for better thermal conductivity between the CPU and the bottom of the heatsink. As it will smooth out the base, the heat will be able to travel directly from one surface to another, resulting in better thermal conductivity. Thermal paste is used as a "gap filler" for these rough surfaces.

Anyway, I went online and got my hands on some wet and dry paper with the following grits: 400, 600, 800, 1000, 1200, 1500, 2000 and 2500.

When I recieved them, I got to work straight away.

This is what the base looked like when I first started.





These pictures were taken after I cleaned the surface with thermal insulation material cleaner. As you can see, the surface is very rough, even to the touch. There are lots of blemishes. Not good for heat transfer!

I took my time doing this as it was my first try at it, and I didn't want to mess up a £35 heatsink and fan. So, I taped the 400 grit paper to a glass surface, because a glass surface is about as flat as you'll get, and the heatsink will only be as flat as the surface you lap it on. Then I wet the paper, let it dry out a little, then used a little washing up liquid on the base of the heatsink and then, without any pressure, glided the heatsink in one direction across the paper, allowing it's own weight to do the work, holding it at the bottom so it wouldn't slip out of line. After about 10-20 strokes across the paper in the same direction, I turned the heatsink around 90 degrees and then did the same. after a few 360 degree turns I would re-wet the paper and re-apply the washing up liquid to the base of the heatsink. I continued to do this until I felt as though it was about as good as I'd get with the current paper I was using.

I then continued to do the same with the 600, 800 and 1000 grit, and about an hour and a half later, this was what it looked like:





As you can see, it looks so much better than before I started, but it still didn't feel completely smooth. Then it was time for the very fine papers.

I then continued the same method with the 1200, 1500, 2000 and lastly the 2500 grit papers. Another hour and a half later, this is what the final result looks like:





Personally, I think it looked better after the 1000 grit, but the difference was the smoothness and the shine. I knew I wouldn't get it absolutely perfect, but as you can see, the flash from the camera is reflecting much more on the final result, and felt as smooth as the glass I lapped it on.

When lapping, some people use polish to make the surface mirror-like. This is not recommended, as it contains oils which will get in the way of heat transfer. It will also make it hard for the thermal paste to burn in due to it being oily, and will probably slide out from the base of the heatsink quicker than usual. Besides, who cares what it looks like? You won't be able to see it anyway

I then cleaned the heatsink base and CPU of any excess thermal paste using TIM cleaner, reapplied some Arctic Silver 5 and turned my computer on.

Unfortunately I don't have any pictures, but it has actually knocked a few degrees off my temperature, especially when loaded. As an idea, I have a speed reduction cable on my CPU fan to minimise the sound as I like my computer silent. With that, before the lapping, at full load it would reach around 45-50 degrees depending upon ambient temperature. It is now sitting at 41 degrees with Prime95 running for the past 11 hours. I am running Prime95 to check temperatures and "burn-in" the thermal paste, and hopefully in a couple of weeks time when the thermal paste has properly burnt-in, my temperature will be even lower still

[alan2273]

For a few degrees, I would not have the patience.
But you have done a good job.

[Joshuashawharvey]

Thanks . To be honest I didn't think it'd take me as long as it did. It's probably because I was trying to be careful and not wanting to go wrong with it. Not having very steady hands doesn't help either. I think if I did it again I'd be able to do it in much less time and make a better job of it.

I've seen much better looking attempts, but at the end of the day it's not what it looks like that counts, it's how it performs, and that few degrees knocked off is a few degrees I can use to making my computer even more silent .
My system is more-or-less inaudible, and that's the way I like it, so any measures I can take to knock a few degrees off without sacrificing the silence of my PC is time and money well spent in my opinion .

[samjohnson]

Nice job Josh! I am with Alan, I would never have had the patience to do that lol.

You would hate my computer. I have six fans running. 4 120mm and 2 140mm.
Oh then I got the PSU fan and of course the CPU fan. lol
It really isn't all that loud though.

The only other thing you need is a SSD. Then you wouldn't even have the hard drive noise.

[Joshuashawharvey]

I bet all of that keeps your system very cool though

I have another system which is not quiet at all, but considering this one is in my living room, I would prefer it to be as quiet as possible.

I have 4 120mm fans, 1 80mm fan, the CPU fan and the PSU fan. I have fan speed reduction cables on all of my fans, and the fans are very quiet anyway without the restrictors.

Yeah you're right about the SSD, but they are really out of my budget

I am considering getting a Western Digital Green Power hard drive as apparently they are very quiet drives. They also use half the power of a conventional drive so that's another bonus. I also have a Zalman hard disk silencer which seems to do a good job with my current hard drive, although I can still hear it a little due to how quiet the rest of my system is.

My CPU is currently sitting at 24 degrees, which to be honest is excellent considering how quiet my system is.

I will post some pictures of my system once I've finished with cable management and what not

[alan2273]

Looking forward to the pictures.

[samjohnson]

Wow thats actually quite good temp right there. My CPU with all my fans runs at like 30C idle. But thats probably because I have a stock heatsink and fan.
Ya the SSDs are rather expensive. I would probably get one myself if they weren't so much.

[Daveskater]

Nice one mate, I don't know if I'd have the patience either

My CPU is usually about 32C when I'm not doing a lot, and that's with a Zalman hsf and a Fan Mate 2 turned down all the way. It's pretty quiet but not as quiet as my PC at work, now THAT'S silent Although I bet it has poor cooling

I'm having a look at Speedfan right now, and my CPU is at 33C. That's with FF, MSN and WMP running.

Looking forward to the pics

[Joshuashawharvey]

I tried to use a Fan Mate 2 on my CPU cooler but for some reason it didn't work.
My CPU fan at default is around 22dbA. I'm running it with a 5v fan speed reduction cable which came with one of my Noctua fans, it's around about 12dbA with that. When I unplug my hard drive, the CPU fan is still just ever so barely audible, but only if you are very close to the system.

My CPU when it was 22 degrees was with an ambient temperature of about 18 degrees and I was running IE and MSN.

That reminds me of the computers at the college I used to go to. They were absolutely silent, but guaranteed they had shoddy cooling
They were SFF computers and the only cooling they had was a CPU fan and some vent holes in the case.

I'll try to get around to posting some pics tomorrow