lapped or not lapped.

[[AK]Zip]

This will work for all Heatsinks and water blocks. We all know that SwiftTech has one of the better lapped blocks and heatsinks, but is it good enough? To me I don't think so. I just received my MCW20-P for my P4 Northbridge and as always no surprised this is what I look at first and see this:



It’s defiantly not the worst I have ever seen but it’s not great. I would say its average. My guess would be 400-500 grid. Well I have done a lot of testing through the past 7 years I have been working with and making my own blocks before any of these companies existed. I know for a fact that the better it’s lapped the less thermal grease goes between the block and the chip allowing the best performance. So I went right at it with 1000 grid and then 2500 grid sand paper and here is the result:



This is what I call a well lapped block. I was no longer able to get my hands on 3500 sand paper so it’s not the best of my work but it’s not bad at all. I am happy with it and I want everyone to have a well lapped water block or heatsink like mine. If anyone has any questions on my theory or questions at all feel free to ask but I know for a fact this will drop temps.

Enjoy,
Alex

[EnJoY]

I think everyone would agree with you on your theory Alex. I also believe that the majority of us have already heard your theory before from many other sources. It is not news to me that a smooth flat surface is better for cooling than a rough scratched up one. Thank you for reiterating this point though, I personally appreciate it. Nice work on your block.

P.S. My name is also Alex.

[[AK]Zip]

I would also like to say that the lower grid on the inside of the block the better, but the higher the grid on the outside the better. I do know that this has been stated before, but I would just like to reinforce it because I have seen more and more people lately just putting on the WB or HS on their computer as is without lapping it...

[Prandtl]

mirror finish (especially if you made it by hand) is no guarantee of quality. I am curious, what surface have you use to lap the wb? can you guarantee that the flatness of the surface you use is better than 0.0003"??

[[AK]Zip]

Originally posted by Prandtl
mirror finish (especially if you made it by hand) is no guarantee of quality. I am curious, what surface have you use to lap the wb? can you guarantee that the flatness of the surface you use is better than 0.0003"??

yes. I have almost everything at home that a machine shop does. I know for a fact that the block is FLAT.

[Lithan]

What method of lapping do you use?
Do you press down on the block or only use its own weight?
About how much sandpaper of each grit did you go through for that result?

[Fpsfreak]

Originally posted by [AK]Zip
yes. I have almost everything at home that a machine shop does. I know for a fact that the block is FLAT.

I assume that you are using a glass plate or some form of metal plate as a base for your lapping procedure. You don't say wether you hand lap your blocks or use a machine so This is purely based on hand lapping of surfaces.

I have hand ground Telescope mirrors for the last 11 years and I can assure you that if that block was hand lapped there is no way that block is within the tolerances of 0.0003 of an inch. Simply due to the motion one would use in lapping any surface it is impossible to achieve that level with your bare hands. Figure 8, 1/4 turn regardless of the technique itwill not be that flat.

For a true "Perfect" Match the block should be lapped using the CPU as the base with a liquid polish matrix between them but this is, to me total overkill.

Now on the other hand if the block was flat milled and further polished by machine than that tolerance is well within reach.

Now that that has been said I think the block looks excellent and should provide some very nice contact area with the core. For a hand lapped block it looks nice.

[[AK]Zip]

Originally posted by Lithan
What method of lapping do you use?
Do you press down on the block or only use its own weight?
About how much sandpaper of each grit did you go through for that result?

I have used both a machine and hand lapping, but in thise case I hand lapped it. I used a block of glass. 300-440-1000-2500 is the order I used. I usually use 3500 after that and then use a polish wheel for a almost 100% flat surface.

BTW I do lap my CPU. Both my P4 and T-Bird. Crazy? yes maybe and most like probably, but it works great!

-Alex-

[charlie]

yeah, crazy or not.... it looks nice!

C

[pcw]

I read somewhere that if you lap more than 1200 grit there won't be any performance gains cuz the the "microscopic valleys" will be too small for the thermal compound to blend in... that's what I've read at least.. but it sure looks good for a couple of mins before you mount the block

[h0ok3r]

Originally posted by charlie
yeah, crazy or not.... it looks nice!

C

hehe yeah shame that when you put it on your NB you cant see it anymore. Maybe you should just leave it off and use it for a mirror

[insulglass]

Originally posted by pcw
I read somewhere that if you lap more than 1200 grit there won't be any performance gains cuz the the "microscopic valleys" will be too small for the thermal compound to blend in... that's what I've read at least.. but it sure looks good for a couple of mins before you mount the block

No neccessarily so.

While the majority of the improvement does come before the 1000-1200 range, there is SOME improvement by lapping further. Also, this difference is greater if you use a thermal compound with really micronized particles, like AS5.

Dave
insulglass@easypckits.com
www.easypckits.com