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View Full Version : lapped my Q6600 (pics and results)



graysky
06-07-2007, 07:26 PM
Well, after lapping my HS, I've had this nagging little voice in my head telling me to do the same from the CPU. I did the job with 800 grit sandpaper. Initially, I told myself I'd just buff what's there right now just to see if it's level. After about 30 laps in one direction and 30 in the other direction I discovered I had quite a concave IHS. So I just kept at it. Two 9x11 pieces of 800 grit later paper later I was left with a darn flat layer of copper looking back at me. I finished the job and put a mild shine on it with a sheet of 1000 grit I got from the local auto parts store just for the f*ck of it.

Here are a few pics and the temp. results I got from lapping both my CPU and HS. I would recommend that anyone wanting the best $20 decrease in temps should consider lapping both the CPU and HS.

Hardware details: Q6600 @ 9x333 and vcore of 1.2625V in the BIOS, P5B Deluxe (vdroop modded) cooled w/ an Ultra-120 Extreme (lapped) with Scythe/s-flex SFF21F 1600RPM fan, in a P182 case:

Temp results:
http://img227.imageshack.us/img227/926/finaldu4.gif
Each temp. point represents an average of data collected over approx. 1 h time period during the 2nd pass of a 2-pass x264 encode of a 720x480 DVD source using a high quality video profile. Data points were logged by Speedfan every 3-4 seconds over this time period. The average CPU usage was >99 % on all 4 cores throughout the experiments. Also room temp was between 20-22 °C.

This is my preferred setup: 8x10 piece of glass on a flat counter top. You can see I cut the sandpaper into a thin strip (about 2-3x the width of the CPU) and attached it to the glass with some tape. The glass is in turn tapped down to the counter top to keep everything immobilized. You'll want to moisten the sandpaper with some mildly soapy water (like 1 drop of dish soap in 1 liter of water), then blot it until you have no pools of water. Remember, if you get water into your chip you're sunk. Then simple hold the chip and gently move it front-to-back. I don't recommend doing circles since they tend to give uneven results. The copper color on the sandpaper is material I just removed from the IHS on the chip.

http://img175.imageshack.us/img175/4587/sandpaperwr5.jpg

Remember, you're after a flat chip here so don't push down on it as you lap: let the weight of your hands do it without extra pressure and go slowly so you don't use uneven pressure. After about 30 laps front-to-back, I gently blotted off the chip with a moist paper towel to remove the metal particles I just sanded off, then rotated it 90 degrees and repeated 30 laps front-to-back. Then you'll want to clean off the sand paper (add more water, then blot it damp and repeat). I'd recommend changing the sand paper frequently since it's really doing the work for you. That's basically it. You can start with 400 grit or so and lap until you can't see variations in the surface of the chip (no silver color is often a good indication that you're flat), move up to 600 or 800, then finish off with 1000 or 1200. I did mine entirely with 800 and 1000, it just takes longer with finer grits. Remember, the key is FLAT, not shiny. I would recommend that you do NOT polish the chip with a metal polish since you'll leave behind a residue that will hurt your heat transfer.

You can test the flatness at any point during the lapping process by carefully placing a razor blade across the surface of he chip and looking at the area where the razor meets the chip. Now position your eye so that you're level with the chip and pointing at a light source (a lamp will do nicely). Do you see any light coming though? If so, keep at it. Another test you can do is to take a black sharpie marker and make about 9 dots in a 3x3 grid on the surface of the IHS. Lap about 5 times, rotate, and do 5 more. Now look at the dots... did they wear off evenly? If not, keep at it. You can also simply draw an "X" from corner to corner on the chip and do this as well. Again, you'll looking for even wear.

After about 5 minutes of lapping in each direction with 800 grit. You can see how the nickel plating has come off around the edges first which shows you just how concave this thing really was:
http://img504.imageshack.us/img504/1487/lap1dd9.jpg

After more lapping most of the nickel plating has been removed expect in the really low areas (the camera flash fired so close to the chip makes all the scratches show up much more so than they do under normal light):
http://img504.imageshack.us/img504/1806/lap2rx6.jpg

Switched to 1000 grit, here's the result:
http://img504.imageshack.us/img504/7767/lap3nt9.jpg

Another angle shows the nice dull reflection, still very so slightly concave at the extreme edges, but good enough for me:
http://img504.imageshack.us/img504/8664/lap4hc5.jpg

I would recommend that anyone wanting the best $20 decrease in temps should consider lapping both the CPU and HS.

Oh, I also thought I'd mention that before I lapped the chip, I had a pretty big difference in core temps when loading with prime95 or 2x orthos: up to 6 degrees C (sorry I don't have a screenshot of this). Lapping the chip REALLY evened-them-out as you can see from the coretemp numbers after the IHS and base of the heatsink were lapped (stressed using prime95 v25.3):

http://img515.imageshack.us/img515/6840/closena8.gif

The table I showed above was not based on prime95 or orthos, it was based on x264.exe which is a video encoder. It is good at using all 4 cores, but not as efficient as prime95/orthos which explains the differences in temps from that table.

Nicepants42
06-15-2007, 09:02 AM
I'm surprised you haven't received any comments yet!

I'd like to thank you for taking the time to gather this information and post it. I am going to give some serious consideration to this come July 22nd.

My only question would be this: Have the decreased die temperatures allowed you to attain a higher stable overclock (maybe with a little more voltage)?

Also, since I've never dealt with the LGA775 socket, what's the best way to hold the cpu while lapping it?

Bipidri
06-15-2007, 01:43 PM
mine was very nicely water-sealed, so even if I could get water at the level of my finger tips / or where the IHS touches the PCB, my E6600 never malfunctionned.

I lapped once with the black plastic protector on, and once without it. and I applied pressure at different points (holding it differently so to speak) at times. the only thing you'll notice is that once you go higher in grits (1000 and upwards) you will need to apply much more gentler pressure. when I did my finishing paper (2000grit) I only let the gravity of my 2 fingertips do the back and forth motions, since things are so smoooooooooth at that level of lapping.

graysky
06-15-2007, 02:37 PM
I'd like to thank you for taking the time to gather this information and post it. I am going to give some serious consideration to this come July 22nd.

Always glad to share with the community; glad you found it useful.


My only question would be this: Have the decreased die temperatures allowed you to attain a higher stable overclock (maybe with a little more voltage)?

Also, since I've never dealt with the LGA775 socket, what's the best way to hold the cpu while lapping it?

Yes, to your first question, but I have since lowered it to 9x333 which gives much better temps.

As to your second question, I just held it between my thumb and two fingers.. whatever feels natural and allows you to control it I guess it the right way.

graysky
08-06-2007, 04:34 PM
I just edited/updated the first post of the thread with a few more pics and a brief description of how I lapped the chip for anyone interested.

jcgamo88
08-07-2007, 03:42 AM
I did this to a celeron D 2.53GHz Prescott. I'll put up some images. I haven't yet put it back in to test bios temps, instead I've been running the machine on an old laptop chip.

graysky
08-07-2007, 04:02 PM
Looking forward to the post.

signmeuptoo
08-07-2007, 05:34 PM
Just lapping my XP-120 and changing to Coollabs Liquid Pro Liquid Metal and I saw temps drop as much as or more than 14 degrees, and I never lapped the IHS. Re,moving it can be better even, but risky to the chip!

jcgamo88
08-09-2007, 12:13 AM
Sorry, took me a while to get my lazy butt to do this. The images might be a bit large =\

I have a 12cm fan mounted to the power supply just above the HS feeding it more than enough air and the proc still idles at 43C and then loads at 59C. Sometimes after a load it likes to then jump to 63C and stay there until I hit it with subzero liquid from my compressed air can.
http://www.fileden.com/files/2006/11/28/432843/gar.jpg

I also don't have the mounting bracket or a proper HS :s

Here's my setup drying, after I finished:
http://www.fileden.com/files/2006/11/28/432843/gar%20011.jpg

I tried to be careful about loading the paper (having metal particles get lodged into the paper) so I'd be able to avoid scratches and use the paper at least one more time. Unfortunately I don't think I used enough water and the results were thus:
http://www.fileden.com/files/2006/11/28/432843/gar%20012.jpg

What I did was to dunk the paper into the basin of water and then place the paper on a piece of glass. the wetness on the glass help prevents the paper from slipping around. I like to call it the reverse "slip 'n slide" effect. :P

Also I wanted to use a lint free cloth (Paper towel is often lint free) that was wet to wipe off the processor each time I submerged the paper again and rinsed the basin. However I totally forgot and that mgiht be another reason for the paper loading.

I turned the paper on end so it stood tall rather than sat wide. I stroked the processor on the bottom 1/4 of the paper about 10 - 15 times with 1 finger lightly touching. Somehow I've mastered a trick whereby using 1 finger, upon each stroke the processor turns a little bit therefore eliminating my need to phsically turn the processor myself 90 degrees every now and then. After about 15 strokes I moved the processor up another 1/4 until I reached the top. Then I'd submerge the paper into water again and repeat twice more.

I was careful to also dump the water from my basin when I switched grits, wipe off the sides, rinse, and refill the basin for the next grit. Unfortunately in the 2 hours of doing this I failed to rinse every now and again and I suspect that is the reason for the paper loading.

I used many grits to also ensure I first removed the nickel, and then to finally polish the copper well. In order of course to fine I used: 180, 220, 280, 320, 400, 600, 800, 1000, 40micron, 25m, 20m, 15m, and 10m.
http://www.fileden.com/files/2006/11/28/432843/gar%20007.jpg

Afterall was said and done the loaded paper caused the processor to appear scratched up, but still reflective. The purpose of lapping is not only to remove the less conductive nickel on a processor's IHS, but to polish the copper so to remove more of the microscopic troughs and trenches which AS5 or other thermal compounds are used to fill.
http://www.fileden.com/files/2006/11/28/432843/gar%20010.jpg

And don't worry, no water entered the hole in the IHS (what the ehck is that there for anyhow?!). I was surprised by this. But some of the metal particles actually build up in there also helping to seal it off until I was done and cleaned it out.

In the end the copper was reflective and exposed. I've yet to test the heat again because unfortunately I'm not made of money and I'm running out of AS5 :( You can be sure thought that when I do test it I'll post here first.
http://www.fileden.com/files/2006/11/28/432843/gar%20014.jpg

never mind the bits of solder in the background here. Just remnant of my attempt to remove and AGP riser and place it onto an OEM board that has the space, but was cleverly left off to cut costs.

graysky
08-09-2007, 04:03 PM
Crazy... that's in interesting method for wetting the sand paper... I used a squirt bottle and paper towel. Anyway, you did all that work (insane amount of sandpaper by the way, I just did 800 --> 1000), and you're out of TIM to test it with??

jcgamo88
08-10-2007, 04:53 AM
Yea, like I might ahve said, I don't even ahv ethe cheap stuff that comes with 3rd party heatsinks =\

Besides that, the only computer I ahve that the proc would fit in I'm wanting to give away to a friend with a lesser proc in it so it would be an even larger waste of thermal grease just to test it and remove it and use more paste to replace the other proc again.

Unless someone's got an old s478 board sitting around collecting dust they'd like to send me at shipping cost :P

jcgamo88
08-22-2007, 11:31 PM
I just got a hold of a P4 northwood @ 2.53GHz that I'm going to lap. A friend gave me some cheapo radioshack silicon grease so I'll be able to then measure the effect of AS5 after the lap too.

I'll do the initial heat tests for unlapped, and the test immediately after the lap with the radioshack silicon. Then replace it all with the AS5. Each test will use all fans throttled to 100%. Idle temp will be taken after leaving the system alone for 5 minutes after boot.

Pre-lim on the P4 is as follows:
http://www.fileden.com/files/2006/11/28/432843/MWSnap001_thumb.png (http://www.fileden.com/files/2006/11/28/432843/MWSnap001.png)
---
http://www.fileden.com/files/2006/11/28/432843/MWSnap002_thumb.png (http://www.fileden.com/files/2006/11/28/432843/MWSnap002.png)
The following is the ambient temperature. Outside is the very inaccurate temp of the IGP heatsink just after I was done with the Orthos test. "Inside" is the ambient temperature around the keyboard which is only about 1 foot from the actual case.
http://www.fileden.com/files/2006/11/28/432843/comp%20014_thumb.jpg (http://www.fileden.com/files/2006/11/28/432843/comp%20014.jpg)
---
http://www.fileden.com/files/2006/11/28/432843/comp%20015_thumb.jpg (http://www.fileden.com/files/2006/11/28/432843/comp%20015.jpg)

I should have the final results in a day or two depending on homework!

ww2717
08-31-2007, 02:13 AM
Where did you obtain the 40micron, 25m, 20m, 15m, and 10m sand paper from? Can you provide a link thanks.

Spawne32
08-31-2007, 08:35 AM
this is gona sound kinda retarded but, what program did you use to make that chart and get the grid information on the bottom. I need to do a similar chart myself ;)

graysky
09-09-2007, 04:34 AM
this is gona sound kinda retarded but, what program did you use to make that chart and get the grid information on the bottom. I need to do a similar chart myself ;)

Just excel :)

jcgamo88
09-11-2007, 11:04 PM
Where did you obtain the 40micron, 25m, 20m, 15m, and 10m sand paper from? Can you provide a link thanks.

Oops, I still haven't gotten around to lapping :(

The micron sand paper I obtained at an auto detailing store in town which specializes mostly in exterior custom effects.

The first time I lapped anything though, I used a kit from http://www.easypckits.com/

graysky
09-12-2007, 03:09 AM
@jcgamo88 - you can just use 200 or 320 as your coarse grit, 600 or 800 as your fine or medium and maybe 1000 or 1200 if you want to... just be sure they are quality wet/dry papers. Anything else is overkill.

dede99
11-02-2007, 02:16 PM
Think I'm going to Lap my Quad also, every single Celsius is welcome :)

graysky
11-02-2007, 03:16 PM
Cool... be sure you do a before/after analysis. Run p95 for like 45 min and record the room temp and coretemp temp's before and after. Also be sure to let us know how it went. You might wanna take some pics before, during and after for your own reference later on for whatever reason since you'll have it apart.

shovenose
10-29-2010, 10:50 AM
Doewnt this take the writing off the chip? Cuz yo cant really sell it when youre done with it then?

Tator Tot
10-29-2010, 01:50 PM
Doewnt this take the writing off the chip? Cuz yo cant really sell it when youre done with it then?
It does take the lettering off the top of the chip, but you can still sell it.

Lapped CPU's usually take a higher price in the market (for enthusiasts) than non-lapped CPU's.
Strictly because lapping gives you better temps when you lap the Block/Heatsink & CPU.

Zero82z
10-29-2010, 09:37 PM
You really needed to revive a thread that hasn't been posted in for three years?

shovenose
10-29-2010, 10:25 PM
lol i guess i did :)