AMD IHS not Flat

[Evo85]

So, in my never ending quest to get lower CPU temps, I have been reading about lapping the IHS . So, decided to take my CPU out last nite and check the flatness of the IHS. I took my fresh razor blade and held a light behind it and could see a pretty good gap. A little surprised, I took a piece of notebook paper and checked and sure enough, the paper would go between them (although just barely).

Is that much gap common? I checked my stock 5400 and it was almost as bad too. I would like to know if other AMD owners have run into this.

Regardless, I have found my project for this weekend.

 

[phanbuey]

yeah... thats why everyone who wants better thermals ends up lapping eventually... ive never seen a perfectly flat IHS unless i made it that way.

Its just as bad for intel too.

 

[Binge]

i7s for the most part are convex, the edges are rounded down.

 

[kyle2020]

Id love to summon the courage to lap my quad - I lapped the fuzion I had, but wet sanding a processor . . . makes me shiver lol.

 

[dark2099]

Id love to summon the courage to lap my quad - I lapped the fuzion I had, but wet sanding a processor . . . makes me shiver lol.

IHS' are usually pretty thick so no chance of ruining the chip less you sand for many hours.

 

[Esse]

Wet sanded an old 4000+ as temps were fairly high. After that I haven't hesitated to do every other CPU

Mind you removing the IHS is so much easier. Not exactly good for resale value though.

 

[HolyCow02]

lapping scares me... i feel like I would f the whole thing up...

 

[AphexDreamer]

Would it do more harm or good if I were to lap my THERmaleright Ultra Heat sink with just some sand paper I have sitting around? Is there harm to a crappy sanding?

 

[ascstinger]

lapping a 775 processor is easier imo, no worries about bent pins.

 

[phanbuey]

lapping a 775 processor is easier imo, no worries about bent pins.

for sure... i remember bending pins back with tiny tweezers for my 754 chips.

 

[kyle2020]

IHS' are usually pretty thick so no chance of ruining the chip less you sand for many hours.

its not that, its just moisture + chip = bad. Knowing me id somehow screw it up lol.

 

[crtecha]

Same. I want to work up the courage to give it a go. Once I get my Phenom II I think ill give it a shot on my current cpu. As long as I have a running machine I dont really care. But I would hate to waste hardware.

 

[Fatal]

Lapped my AMD X2 6400+ BE today so far only 4c idle drop I know the thermal grease has to settle. I can say it is worth it the IHC is not flat well mine was nowhere close. I won’t know how much of a temperature drop I received but will post when I do. You just have to take your time took a bit over 2 hours.

 

[hat]

I want to lap mine until I grind it down to the copper on the IHS but I'm not exactly sure how and I don't have the tools either. I know a rediculously high grain sandpaper is good, like 2000 grain

 

[crtecha]

Id just go with this guide its pretty through

http://forums.techpowerup.com/showthread.php?t=41080

 

[jagass]

I think lapping is too risky...

 

[kyle2020]

Id just go with this guide its pretty through

http://forums.techpowerup.com/showthread.php?t=41080

thanks for the link

 

[MilkyWay]

the correct term is glass paper people not sand paper

wet n dry paper too is for things like metal, i wouldnt use like a powertool lol

edit:your supposed to sand in a circular motion too not up and down, dont ask i got an intermediate 2 A in practical craft skillz

 

[Frizz]

Haha I lapped my Q6600 without any care, it not broken though but im completely unsure if its still even or not, all I know is I get 4 degrees higher on core 1-2 compared to core 3-4.

I just forgot about what it was costing me! All I thought about was that extra 1-5 degrees difference ^^

 

[Evo85]

I broke my sandpaper out and removed my CPU last night. I started out with 420 grit, then moved to 800, then 2000 grit to finish. Took me about 2 hrs to do the job. I was completely amazed at how much I had to remove to get it flat. But never during the lapping did it feel like I was going to break through. My main focus was on getting it flat, and not so much the finish ( I wasnt looking for a polished, mirror like finish).

To help protect the pins, I used the dense foam protector that came with the CPU from AMD. It spread the load out very nicely!

I did a OCCT stress test and wrote down my temps after 20 mins. I will compare those with what I get after the lap job.

 

[silkstone]

your supposed to sand in a circular motion too not up and down, dont ask i got an intermediate 2 A in practical craft skillz

I believe its actually best to sand in straight lines. Count the amount of strokes, rotate, repeat. If you sand in a circular motion it is quite easy to get a convex IHS at the end if you dont apply equal pressure. I've always lapped my CPU's from the celeron 333 upwards and never broken a chip, even dropped my current one on a tile floor from 1m. I said a short prayer after put it back in my pc and before i pressed the power button

 

[kyle2020]

I believe its actually best to sand in straight lines. Count the amount of strokes, rotate, repeat. If you sand in a circular motion it is quite easy to get a convex IHS at the end if you dont apply equal pressure. I've always lapped my CPU's from the celeron 333 upwards and never broken a chip, even dropped my current one on a tile floor from 1m. I said a short prayer after put it back in my pc and before i pressed the power button

|When I did my fuzion I did up down strokes, counted 30 up down strokes, rotated 90 degrees then did the same. Only took me and hour.

 

[silkstone]

Yup, mine took me less than 30 mins - if i remember correctly i got a 9C drop after applying better TC as well

 

[Thrackan]

I'm thinking about actually lapping my i7... But I'm slightly hesitating.

 

[Evo85]

Would it do more harm or good if I were to lap my THERmaleright Ultra Heat sink with just some sand paper I have sitting around? Is there harm to a crappy sanding?

A bad lapping job could do more harm then good.

Read this. Excellent article by Wizz.

http://www.techpowerup.com/articles/cooling/air/39

Some other great threads on lapping the IHS:

http://forums.techpowerup.com/showthread.php?t=32771&highlight=Lapping+IHS

http://forums.techpowerup.com/showthread.php?t=40038&highlight=Lapping+IHS

http://www.overclock.net/faqs/15897-info-want-lap-your-p4-s.html