Madshrimps Forum Madness - Lapping a P4 IHS: any good?

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nice photoshopping =)

the originals are high resolution scans of the IHS - shows about every detail you want :)

and to set the record straight:
picture number 12, bottom right corner, shows the P4 in the same state as it was in the reflection-pic, post 2 on this page

odd, it doesn't look quite as polisched from top view :)

high resolution scanners reveil even the smallest scratches on most perfect lapped surfaces

people had comments afterwards also about the roughness of the surface, while IRL it's really flat
http://www.madshrimps.be/forums/show...2753#post42753

I don't need a scanner to see that my SLK947U's base sucks, it realy need to be lapped :D . And a mirror doesn't mean a good contact.
I have here an old Duron Alu heatsink wich I tried to lap (didn't realy worked :D ). If u look from the top, it's blurry, scratched and has different colours. At a very sharp angle, it's like a mirror, but it is concave :grum: -> bad CPU contact.

How are those temp readings TerA?:)

here's something I found @ XS's forum

Quote:

Originally posted by Axle Gear
Recently, I bought a lapping kit from Easy PC Kits to lap at the heels of my heatsinks.

I got the coarse, and premium kits, as well as the polishing gel, all for just $16.25. I've seen premium kits sell for $30+.

The premium kit includes grits of 400, 600, 800, and 1k. And also 40, 25, 20, 15, and 10 micron pads. Also included is a square glass peice, to give you a nice flat surface to work on.
The gel is 10k grit, and resembles watery cocaine. Extra points for that one. ;)
The coarse kit includes 180, 220, 280, 320, and 400 grain. Looking at my heatsinks, I figured i'd need it!

For this test, the victim will be the
DC1206BM-L/610-P-CU Copper Core Dense Textured Microfin
Since I have a few laying around. I've found them to be notoriously poorly lapped, and furthermore have this thermal pad-like goo on them, which is a pain to remove without scratching the heatsink. It will be applied with Arctic Silver Ceramique (which EasyPCKits threw in lovingly extra, along with some zip ties, for no charge!)

Temperature readings will be taken at a stable 70F after the thermal compound has had at least 48 hours of cycling to set in.

The heatsinks are notoriously badly lapped. You can make an audible scrubbing noise by running your finger over them, and the mill lines look to be about hair-width. In other words:
It looks like they cut it out with a fork.

I'll take readings of idle and high loads before, and after the lapping, and keep y'all updated on the results.
If the results show well, i'll repeat with a copper-core TR2-M2, which is a much better heatsink, but also a victim of not-so-great lapping.

follow up @ http://www.xtremesystems.org/forums/...threadid=38064

I lapped every heatsink I use after testing was done.

Another point from industry experience in metal and paraffin wax; any transformation from liquid to solid will creates craddle during cooling process which can be left at ambient temp to cool or accelerate cooling process by blowing air across; or going thru refrigerated tunnel. Whichever method you take the surface of the metal would become convex. This could be corrected today using highly accurate temp control measurement to melt metal to just a few degrees above it's melting point. Cutting generates heat also; unless expansive equipment is used. (I don't believe the factories in China is using no heat cutting equipment).

The secondary machining to make the surface flat and smooth is very costly. Don't expect to pay $10 to $30 and get a perfectly flat and smooth heatsink. Vibratory finish will get better result; again cost more.

Lapping your heatsink will almost always yield better result if done correctly.

Well we are back with some non conclusive results for the lapping kit our friend insulglass send us. TerAngreal lapped his P4 as you can see in the pics above; after a couple of weeks of temp monitoring before/after no real difference was seen.

but as insulglass mentioned, the biggest impact will be on medium/poorly lapped heatsinks; I have the kit now and will do some lapdancing soon with some of heatsinks I have lying around.

my procc has a sweet babyass too now :D

i used => grid 180,240,400,600,1000

didn't find 1200 or more on a saterday

what did you use to get it so nice and shiny? cuz I've read articles where they go up too 2500 grid (I think, not sure about the number but it was more then 1200 grid) and then they use some pollish and a linnen cloth but never did I see one that had such a mirror finish before.

actually, going through this thread again, I must admit that the one terangreal did looks just as good to say the least :s

the camera is focusing on the coin instead of the P4 IHS surface, thereby it is out of focus and seems mirror-like :)

Quote:

Originally posted by kristos
what did you use to get it so nice and shiny? cuz I've read articles where they go up too 2500 grid (I think, not sure about the number but it was more then 1200 grid) and then they use some pollish and a linnen cloth but never did I see one that had such a mirror finish before.

i used copperpolisch and cloth