Lapped by Ultra-120 Extreme (pics and results)

[graysky]

The base where the HS makes contact the heat spreader of my chip was 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:


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. Plug: [url=http://forums.vr-zone.com/showthread.php?t=105586=SLi_Dog[/url] wrote a great guide for HS lapping.

$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.





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.

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

I got a MUCH larger drop in temps after lapping the IHS on the Q6600. Lapping both the base of the HS and the IHS of the chip is best.

[Adrian Wong]

More +rep for you!

[PsYkHoTiK]

Nice. At least you didn't mirror finish it. When lapping, mirror finish isn't really needed. You just want it as flat and smooth as possible.

Good job!

[graysky]

Originally Posted by PsYkHoTiK

Nice. At least you didn't mirror finish it. When lapping, mirror finish isn't really needed. You just want it as flat and smooth as possible.

Agreed. Too many people seem to go out and buy a can of brass-o with their sandpaper... big mistake as brass-o has horrible thermal dissipation properties

[mikegas]

Originally Posted by ijkl540

这是新加的空白文章1，可以在UBB可视化编辑器中，添加和修改文章内容。

SPAM? ... mind you .. I don't read Chinese

[Mac Daddy]

Cool on the lapping Graysky I have never tried it

I can't read Chinese either Mike I pinged Chai he can

[Draztic]

Nice lap...dance? No seriously though, nice one. I have been seriously thinking about doing my xp120...I should get off my lazy but and do it already heh.

[Mac Daddy]

Originally Posted by Draztic

Nice lap...dance? No seriously though, nice one. I have been seriously thinking about doing my xp120...I should get off my lazy but and do it already heh.

I am seriously considering doing this with my Katana2 and see what happens. Graysky takes his time on these things and I trust his results more than I would a link to another forum

[Max_87]

There is a reason why Thermalright started making their heatsink bases convex, all of them used to be flat. The main purpose is to concentrate all the mounting pressure on the center of the IHS, at the cost of consistency in mountings; you need to attempt a few mounts to get the most optimal temperature, it's all about trial and error. Does it do better than a flat base? Yes, definitely. It's been tested and proven many times in XS My WB Testing Results, Excel file inside. - XtremeSystems Forums

Swiftech is the first to ship their waterblocks with convex base (Apogee GT/GTX), after that I started seeing Thermalright doing the same thing on their TRUE. EK also does the same thing on their latest EK Supreme CPU waterblock. When Thermalright started shipping their TRUE with convex base, many went "OMGWTF has gone wrong with their QC!" and started lapping their heatsinks

No seriously, don't lap these convex bases unless you are using a processor without IHS.

Some reading on "bowing" aka convex base
The anatomy of a 'bow'. - XtremeSystems Forums
CPU block lapping - XtremeSystems Forums

[Adrian Wong]

Originally Posted by Max_87

There is a reason why Thermalright started making their heatsink bases convex, all of them used to be flat. The main purpose is to concentrate all the mounting pressure on the center of the IHS, at the cost of consistency in mountings; you need to attempt a few mounts to get the most optimal temperature, it's all about trial and error. Does it do better than a flat base? Yes, definitely. It's been tested and proven many times in XS My WB Testing Results, Excel file inside. - XtremeSystems Forums

Swiftech is the first to ship their waterblocks with convex base (Apogee GT/GTX), after that I started seeing Thermalright doing the same thing on their TRUE. EK also does the same thing on their latest EK Supreme CPU waterblock. When Thermalright started shipping their TRUE with convex base, many went "OMGWTF has gone wrong with their QC!" and started lapping their heatsinks

No seriously, don't lap these convex bases unless you are using a processor without IHS.

Some reading on "bowing" aka convex base
The anatomy of a 'bow'. - XtremeSystems Forums
CPU block lapping - XtremeSystems Forums

Hmm... That makes sense, although it does require you to play with the mounting.