Intel 5500 chipset heatsink tuning

Introduction

I am the happy owner of an Asus Z8NA-D6 motherboard. The CPU is ideally cooled by an Intel STS100C which I reviewed 2 years ago. However, I did notice critically high temperatures at the Intel 5500 chipset level, despite the two 120 mm Noctua fans in my tower. When the sensors reported values above 100C, it became clear to me that I had to do something about it.

A document dedicated to the Intel 5500 chipset cooling is available. It describes two different heatsink models recommended by Intel in order to properly cool these chipsets. First one is a rather high model (30 mm) with a 50 × 50 mm base. Second one is a low profile model (12.5 mm) with a 65 × 65 mm base. This difference in geometry suggests that this second model is about 30% less in weight than the first model. Additionally, its low profile makes its cooling by the air flow inside the case less efficient.

Unfortunately, Asus picked the second model for my motherboard. This explains the measured temperatures, typically between 80 and 100C. This technical choice was the only one possible in order to comply with all geometrical constraints, given all the components and slots present on the motherboard. It was certainly an acceptable choice in anticipation of a use in a low height, heavily cooled rack, but that's not my use case. Actually, the relative locations of the heatsink and the case fans are such that increasing the fan speeds has almost no impact on the chipset's temperature.

Furthermore, the document mentions 95C as the maximum temperature the Intel 5500 chipset should never exceed. The risk of damaging my motherboard was serious if I didn't improve the situation quickly.

The noisy solution

The most immediate solution was to add a 60 mm fan on top of the original heatsink. Tried it, it works, very well even. The temperature went down to 35-40C. The problem is that this means one more fan in the machine, so an extra source of noise and heat. Something I try to avoid as much as possible.

The easy solution

Another relatively easy solution: order the other heatsink model and swap it in. The Intel document even includes a list of suppliers. Unfortunately this list is targeted at motherboard makers, not end users. In practice, it is extremely difficult for an individual to get his/her hands on such a heatsink, to the point that I simply had to give up.

Remaining was the less easy, but fun-guaranteed solution, requiring a hacksaw, a miter box and a clamp...

The fun solution

What is very convenient when you have 15 years of computer tweaking behind you, is that you have all kinds of old pieces of hardware lying around. So, I dug up an old Socket A cooling block from my drawers. Its only future seemed to be the waste disposal. I removed the fan. Heatsink dimensions: 77 × 62 × 30 (h) mm. Weight: 180 g. Compared to the poor 55 g and 12.5 mm in height of the original fan, it looked very promising.



On the left hand side, the original heatsink: 55 g, 12.5 mm in height. On the right hand side, the replacement heatsink: 180 g, 30 mm in height.

So, it was looking rather good, however the width was a problem: 77 mm, that was 12 more than the 65 mm of the original heatsink, which itself was just fitting.

This is when I fetched the hacksaw. Seriously, never let a dumb piece of aluminum bother you! I started cutting through the base at 65 mm.

I could have cut it all the way through, but I knew that after about 15 mm there was enough room on the motherboard. So I decided to cut at right angles at this point, in order to keep as much weight as possible. Clearly this was more difficult, but keep in mind that the efficiency of a heatsink largely depends on its weight and its developed surface. By cutting that way I preserved both, removing only 20 g out of the original 180 g. Then all I had to do was file the rough edges to make the heatsink safe to handle again.

One last issue was raised when I had to tighten the tuned heatsink on top of the chipset. Its base was 4 mm thicker than the original. This difference would have increased the tension applied by the torsional clip, and I feared it may damage the chipset. So I decided to increase the depth of the central gap, by about 3 mm. It's harder than it seems, because you always have a tendency to saw more on the ends and not enough in the middle. And if you go too far, game over, the heatsink is split in half. But with a bit of patience I succeeded.

Conclusion

Here comes the new heatsink, installed. You can see there's just enough space for the graphics card on one side and the smaller heatsink for the other chipset (underneath) on the other side.

Regarding the temperature, I am very satisfied. The chipset now runs between 63 and 74C, that is 21C lower than before on average. The smaller range can be explained by the increased weight. The maximum temperature is now 21C below what the chipset can handle, which seems totally reasonable.

Summary

Original heatsink Replacement heatsink
Material Aluminum
Height 12.5 mm 30 mm
Weight 56 g 160 g
Temperature 80-100C 63-74C

To be continued...

So you thought it was all over? No it's not!