Zipang Slippage?

[mmgando]

Hello,
I just bought a Zipang for my MSI 7125 motherboard with a socket 939 Athlon 64 3000+ processor. The heatsink works great but I have encountered some strange phenomenon and was wondering if any one else has had similar trouble.

As I am using an AMD CPU I have used the AMD mounting hardware which consists of the two metal clips which interface with the plastic tabs. To start with at the factory setting, the clips were too short to reach the plastic tabs of my mounting frame. I therefore needed to remove the clips and reinstall them on the second notch so that they would properly fit on the mounting tabs. First of all, is this normal? There is no reference to doing such a thing in the scythe instructions but it was the only way for the heatsink to install.

That said, the interface is not perfect considering even after installation the heatsink is able to slide in line with the clips, i.e. vertically in most setups, since they have non fixed pivot points and only truly lock the heatsink in one dimension. Perhaps coupled with this I have noticed some interesting thermal characteristics which might have to do witht he heatsink slowly slipping down after installation and thereby not making proper contact with the center of the CPU which I will attempt to describe below.

note:
I have run extensive temp/silence tests with the Zipang and in the end decided that running the fan at 7V provided me with the greatest amount of cooling/noise ratio, therefore all the following calculations are assuming a 7V fan.

When I first installed the Zipang using a high quality thermal interface material the temps I got at idle with cool n' quiet are only 2.9C over ambient. At load using Toast for ten minutes the temps are 17C over ambient. These numbers are very good and based on the quality of the Zipang and also the fact I use a custom built case designed for cool/noiseless computing.

However, over time these numbers get significantly worse which flies in the face of the "thermal interface materials get better over time as they spread out" convention. If my computer is running for an extended period of time my idle temps can increase to 8 over ambient and at load the temps can jump to 30C over ambient. Most frustratingly, at this super high load number the heatsink doesn't feel very warm making me suspicious about its contact with the CPU.

Adding to my theory that contends that "slippage causes bad CPU contact" is the fact that if I turn my case on its side so the Zipang is no longer "hanging" vertically but is now sitting on top of the CPU, with its mass and gravity forcing a good connection, the temps get a better. If I then give the heatsink a wiggle to remake the thermal bond the temps return to similar levels as when the heatsink has first been installed, not as good, but close. I can then reorient my case so the Zipang hangs vertically again and the temps stay good for a while but eventually they do rise requiring a repeat of the procedure to remake the thermal bond.

Has anyone else experienced anything like this with a AMD mount?

Can anyone from Scythe comment about the phenomenon? Is it ok to used the second notch on the clips? Should my heatsink slip in line with the clips or does that show it is too loose?

Any thoughts would be appreciated!

[sumo]

hy mmgando,

the reason for your problem is based on your modification of the cooler mounting. When you replace the Clips in the second notch you loose the contect pressure to the CPU, and this ends in a bad perfomance. This also declare the performance differences between different positions.

You should remodify the clips and than you musst press the clips in the mounting notches of your retention modul. You need the pressure to provide the best performance.

i hope all is clear for you.

[Tybym]

Hi! Well... I a have almost the same problem. I use a Zipang on a DFI NF4 SLI-DR expert motherboard (hence 939 platform). The issue is that I couldn't manage to set up my Zipang using the first notches (as they were when I opened the retail package). Instead I had to use the first notch on one bracket and the second notch on the other bracket in order to properly fit the cooler. I tried many times to mount the Zipang (with my motherboard outside the case) using the first notches but it was almost impossible. It was so tightly fit that it slipped from the plastic bracket and snapped right away and I was afraid I would break something if I try further.

Now the cooler doesn't slippage (or so I think) but I am still uncertain if I have mounted it as I should have (because of moving one of the notches one level up).

How is the cooler supposed to be installed on a 939 platform: is it really necessary to have both brackets set up on the first notches in order to get a tight fit? I almost broke my fingers trying to do that and I still didn't succeeded. And it's not the first scythe cooler I have or mount (I previously owned a shuriken but it had a different mounting system).

Is there any other (easier) way to mount zipang on a 939 board? Perhaps a bolt through system or the Scythe universal retention kit?

thanks!

[sumo]

hy Tybym,

the mounting is very tight, and you need some pressure to fix the cooler on the brackets. When you move the clips you loose pressure and the contact to the CPU = bad performance. Normaly there should no problems to mount the cooler on the brackets.


Yours faithfully sumo