lapped my ultra-120 extreme (pics and temp results)

graysky

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When my Ultra-120 X and I have to say I'm a little puzzled. The base where it should contact the heat spreader is not smooth at all, it's actually grooved! You can see a scratch which is where I gently ran my thumb nail over the surface; I could feel the rough edges.

Have a look for yourself:
startzy5.jpg


Anyway, others encouraged me to lap it which I've never done before. After wrestling with the idea for a couple of days as well as reading many articles/guides, I decided to give it a go. $20 worth of sandpaper, a $2 piece of flat glass, and 4 hours of careful work (and sweat) later, I was left with a pretty darn flat HS. You can see by the pictures that this particular one was quite concave instead of being flat which isn't good for keeping contact between the HS and IHS of the CPU.

hs1cl9.jpg

hs2wu7.jpg

hs3ok0.jpg


Did it work you're probably wondering. The temp data as measured in speedfan.exe for a ~1 h x264 encode (uses all 4 cores with a CPU load of >99 %). I had speedfan log the temps (which it does every 3-4 seconds) and I averaged the whole data set per core for the 2nd pass of the 2-pass encode (the 2nd pass is the most CPU intensive). Room temp for both experiments was ~23 °C. By the way, I added a constant of 15 to each core in speedfan since it incorrectly displays temps for quads by 15 °C.

System specs: Q6600 @ 9x333=3.01 GHz (stock voltage), P5B-Deluxe in an Antec p182 case.

[code:1:7ddd965cc2]Before lapping the HS:

Core 0: 66.9
Core 1: 66.4
Core 2: 60.6
Core 3: 60.6

After lapping the HS:

Core 0: 64.9
Core 1: 64.4
Core 2: 59.0
Core 3: 59.4

Delta:

Core 0: 2.0
Core 1: 2.0
Core 2: 1.6
Core 3: 1.2[/code:1:7ddd965cc2]
 

graysky

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Here are some pics of the process (they're all in one 1.2 meg file - sorry for your analog modem folks). Anyone tell me what I did wrong?

lappingva2.jpg
 

System48

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I started lapping my heatsinks when I got my 3.2GHz P4. I originally used rough(200-600 grit) off the shelf sand paper and then used a metal polish to smooth it down the rest of the way. That technique was awful compared to what I use now, check this site's products http://www.easypckits.com/products/premiumlk/. Their premium kit goes from 400 grit to 10 micron paper and then they have a diamond compound that's about equal to 10,000 grit paper. I go one step further using an optical grade red rouge that's about 0.7 microns, 60,000-80,000 grit. The finish is perfect, you probably won't see much gain beyond a 2000 grit finish but that mirror finish does look really nice. If you ever have the urge to you can also try out lapping the CPU. I've done it on my P4 but not yet on my C2D, I'll wait till their cheap enough to replace if I ruin it.
 

Gneisenau

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Glad it worked out for you.

BTW, there is a minor problem with the number in your core 0 delta table.

It should be 2.0 not 4.1. Or the numbers for core 0 in the other two tables are bad. :D

Anyway, it's always good when things work out in the end. Keep in mind that the temps hopefully will drop another couple of degrees over the next week. :)
 

graysky

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@Gneisenau - thanks for catching that math error. I fixed the post. You can see the numbers after I lapped the CPU which have greatly improved over what's posted in this thread. Here is the thread about lapping the Q6600.
 

little_scrapper

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If you want a mirror finish then go as high of a grit as you want. If your strictly going for performance then you may as well stop at 600grit. It has been proven time and time again that after 600-800 grit there will be no measurable gains in performance from lapping.

And you can buy SINGLE sheets of sandpaper from ACE Hardware for about 50 cents a sheet. So for less then $2 you can lap your HS.

I only used 200, 400 and 600 grit and it looked like this:
img0069jr1pf9ss5.jpg

I got an immediate 8C drop in load temp.
 

Jake_Barnes

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If you want a mirror finish then go as high of a grit as you want. If your strictly going for performance then you may as well stop at 600grit. It has been proven time and time again that after 600-800 grit there will be no measurable gains in performance from lapping.

And you can buy SINGLE sheets of sandpaper from ACE Hardware for about 50 cents a sheet. So for less then $2 you can lap your HS.

I only used 200, 400 and 600 grit and it looked like this:
img0069jr1pf9ss5.jpg

I got an immediate 8C drop in load temp.

How long did it take to lap your HS using only 3 grades of sandpaper? Did you use oil, or just water? Nice finish btw :wink:
 

blue68f100

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I use to have to polish steel for microscopes. The one thing that most uses over look is a perfectly ground plane for the sandpaper and micro cloth to reside on. The second mistake most users make is trying to lap going in both directions. Doing so rocks the part and round edges. I had tables with variable low rpm wheels which made life easy. Most all were a min of 1 micron, most down to 1/4.

You also want to change directions with every grit change and you don't go to the next till all scratches are gone.

??? Did you lap Both the CPU and HFS. If not this may be the reason for needing more AG5.
 

blue68f100

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Whooow, that was a huge concave HFS. Some of my HFS were concave, but nothing like that.

You had your work cut out for you. But copper be soft is easy to work.

Nice work.
 

graysky

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Thanx. Part of the 4 hours it took was me learning how to do it/developing a system/technique. If I had it to do over again, I'm sure it would be less time.
 

graysky

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Error: server cannot be reached or image not available (timeout: 10 seconds).

Image URL: http://img515.imageshack.us/img515/111/img0004ty1.jpg

I believe if you paste the URL to the pic you'll be able to see it. It think the problem has something to do w/ tg's hardware and not imageshack.
 

eric54

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Do you have to use oil/water to lubricate or do can you just do it dry? If you need to lubricate, what kind of lubricant should be used?
 

jjnguy13

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I've read lots of different tutorials oh how to lap a heatsink; most of them use a little dish soap and water. A few did it dry. And a few used mineral oil. I'd recommend using some sort of lube. It seems to help make things go more smoothly. (obvious?)
 

graysky

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Soapy water is easy. You can also use low odor kerosene to do it; I'd caution you against using mineral oil just because it's so hard to get rid of afterwards.
 

eric54

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Thanks for the advice, so where and how much soapy water should be applied? I just ordered that lapping kit mentioned earlier in this thread so naturally I'd like to know the proper method to use it :wink:
 

I

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The basic principle behind the liquid is not to lubricate, it's to keep the sandpaper from clogging up so it sands faster and continues to do so evenly.

I like to use a good packing tape to tape down the sandpaper to the glass, then take a cup of detergent water and just splash some down. After it gets really dark you can rinse it all off in the sink or with a hose then dump a little bit of detergent water on it again. It doesn't take much detergent, just a tiny squirt into the glass.

Trust me when I tell you a mirror finish is overrated, it has no thermal benefit to get it that shiney, it just makes double the work. Perfection in this is highly overrated, you will get 90% of the benefit in the first 5 minutes so long as you don't start out with too fine a sandpaper, 220 grit is about right if it's concave but otherwise 400 is a good start, and finish - if you don't want to use 800 or higher you aren't missing out on but a tiny fraction of a degree if that.

Some places sell a mixed pack of 3M wet/dry sandpaper that is much cheaper than $20, maybe about $5. Once I made the mistake of buying generic Chinese wet/dry from Harbor Freight. It was horrible quality, brittle when dry and fell apart immediately when wet plus the sand didn't even seen to stick to it, was like they used water soluble glue!
 

graysky

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Thanks for the advice, so where and how much soapy water should be applied? I just ordered that lapping kit mentioned earlier in this thread so naturally I'd like to know the proper method to use it :wink:

From what I've read, front-to-back/back-to-front is the better technique since circular or figure-eight motions can introduce uneven surfaces; you have more control when you minimize the angular motions. I have always used soapy water (like 1 drop of dish soap in 1 liter or so of water). You just want to wet/moisten the sandpaper. Be sure you clean the sandpaper off with water/papertowels between lapping runs. I wouldn't recommend that you do it without. The water lubricates as well as immobilizes the metal partials. Don't worry about using grits higher than 800 or so... I think the most benefit you'll get out of lapping is a flat surface; you can make it smooth beyond say 600 or 800 grit, but as I understand it through reading, the extra mile doesn't give you much if any additional benefit. It does make it reflective, but who cares since it can't be seen once it's installed.
 

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