Lapping success! (56K warning)

[stopthekilling77]

After an initial failure on my part to realize the importance of plugging case fans into the right 4-pin molex connections (in other words, ones that are actually connected to the power supply) I've been impressed with the temperature reduction I've seen!

For those who didn't know or haven't checked my signature banner yet, I've got an E6750 C2D, G0 for those who want to know lol! My heatsink is also in my signature, the Thermalright Ultra 120 Extreme, and I have it coupled with a quiet-yet-effective 120mm Scythe S-Flex SFF21E fan running at 100%. I used Arctic Silver 5 both before lapping and after in order to isolate the effect of just the one variable of my lapping the heatsink. Now for some pictures and some explanations for my madness!

This is my initial shot, I apologize for the bad quality as it was taken with a camera I don't fully know how to use yet.

The little gray blurred circle on the upper-mid left of the base was a little pock/hole in the surface of what I guess is aluminum. Never fear, after a few hours of lapping, it went away entirely!

A little while longer, no copper yet, I believe this is after a few minutes of 600 grit, as you can see the lines but no visible copper tones.


I was so excited to see a few circles of copper show up that I completely forgot to take pictures of them x.x but here is the next stage in my experiment, around 3 pads of 400 grit later.


Not very reflective, but getting better.


And some more improvement...


Then it got fuzzy a little later...


Almost to the finish line!


I almost stopped here but kept on with some 2500 grit!


The final result of my labors! Not a perfect mirror shine, but a huge improvement over the original pocked, rippled, and aluminum surface!


Now that the process has been shown, here's the improvement!
I took a few temperature measurements before the dive: idle/load for completely stock at 2.66GHz at 1.3500v, idle/load overclocked to 3.0GHz at 1.408v
and have taken a few temps after lapping, to match the previous ones: idle/load at stock, idle/load OCed to 3.0GHz. The main difference here is that my post-lapping overclock actually took NO voltage changes to achieve a stable (running Prime95 overnight ~11+ hours full load, still running at the moment)

Temps (in °Celsius):
Pre-lapping stock idle/load: 39°/55°


Pre-lapping OC idle/load: 44°/62°
(forgot to capture the idle temp screen for this category, but I had it written down)

Post-lapping stock idle/load: 31°/45°


Post-lapping OC idle/load: 31-32°/46-47° depending on the minute





I'm definitely happy with the large drop in temperatures! Down the line I will be comparing my lapped temperatures using Tuniq TX-2 versus my trusty Arctic Silver 5!

Thanks for looking!

[Skippman]

Wow! Nice improvements and boy is that shiney! I'm hoping I won't have to do this with my Apogee but I might and using your directions it should be cake.

I think your problem with the first pic is you had it on panorma or some other such setting as the background is perfectly clear but the foreground is all blurry.

[Alathald]

@Skippman - don't lap your Apogee, they are designed to be bowed a little to improve contact and heat transfer...if you want to improve temps you can make sure the IHS on the CPU is nicely lapped though. Just please don't lap that GTZ. Ever.

[DMB2000uk]

20 degrees of temperature drop from just lapping!

I'm in shock and awe!

Job well done mate.

Dan

[Darkstar]

sweet! nice job (i think your camera needs a macro mode though)



Yeah, think you might need to take the pics farther away and then just crop them down so it can focus.

[martini161]

hate to be a pessimist but there must have been something very wrong before hand if you saw 20 degree drops

[stopthekilling77]

There was! there was a freaking hole in my HSF!
Not to mention the fact that the rippling on the aluminum base was terrible o.o

[Bwall]

hate to be a pessimist but there must have been something very wrong before hand if you saw 20 degree drops

It's common with this heatsink.


Thanks for the thread, I've been putting it off since I got mine in May '07 but you may have just inspired me.

[stopthekilling77]

Totally worth it, Bwall! If finding the right kinds of wetordry sandpaper is too tough, FrozenCPU has a lapping kit that might do the job (even though I needed to hit up WalMart for more 400 grit)

[Alathald]

Now that you've made your HSF less grainy, we just need to do the same for your avatar
Looks good man!

[Bwall]

Totally worth it, Bwall! If finding the right kinds of wetordry sandpaper is too tough, FrozenCPU has a lapping kit that might do the job (even though I needed to hit up WalMart for more 400 grit)

Yeah, I've done my fair share of lapping, did a E6300, E6400, E6600, and a few heatsinks. I can get good results with paper from Walmart, no need to spend big bucks at frozencpu.

[Skippman]

I should make you come over and do my E6600 then! lol

[TheGanG]

Good job, 20°C is insane...

[stopthekilling77]

Good job, 20°C is insane...

Wow, thanks! That means a lot coming from you actually. I just need to get this chip to 3.33GHz and I'll be happy. Unfortunately I'm not sure I can do that without pumping a lot of volts through it... It's a poor overclocker.