Reducing Z690 Chipset temp - (Maximus Hero)

[Brigman]

So, I'm not entirely happy to see the PCH on my board ticking between 68-70 celsius in the middle of winter - and that with a slight undervolt applied. And yes, I get that it is still running in spec at this temperature, but if there's anything that can be done to easily reduce it, I'm up for that. So, let's see what's possible.

First let's take the heatsink assembly off and check it out:



The placement of the chipset right in the shadow of the graphics card isn't ideal, but it is what it is and is largely dictated by the signal paths to the PCIe bus and storage anyway. An improved heatsink assembly could be machined if I really felt like it. However, I'd rather give myself an easier time...



The heatsink is nicely finished and has a significant amount of thermal mass, but is very poorly optimised for heat dissipation, having no finning to speak of, as evidenced by the fact that the chipset actually runs very cold over the first few minutes of the system's use - and then slowly warms as the heatsink heats up.

The anodising also looks to be finished with an acetate film-type sealer on the underside, which will have a small thermal insulating effect - especially in the actual interface with the chipset.




Turning the heatsink on its side, we can also see that the textured finishes on its upper surface are appliqués that are (presumably) stuck on with adhesive tape, and have cosmetic value only. This is, on one hand, theoretically undesirable as it will reduce the thermal efficiency of the heatsink itself somewhat. On the other, it may reduce heating caused by waste air blown from the graphics card.

So, there are a few ways in which this situation can be improved. It is not difficult to envisage a way in which a fundamentally superior thermal solution could have been implemented by Asus - a heatpipe with a fin array, for example. It is also not difficult to see how the monolithic aluminium heatsink could have been improved via the addition of some finning to increase its surface area.

In the short term, I'm going to lap/polish off the anodising in the interface area, and replace the stock thermal pad with a TG Minus Pad and see what, if any, difference we see.



Let's see what that does.

And, good, that's made more of a difference than I had figured. Chipset temps are down a good 10-15 celsius with this change. Now idling in the 52-55c range once the system has fully warmed, and peaking 58-60 under heavy load.

So anybody else interested in a quick win in this area, there are a couple of things to try there. Next, I'm going to add some ducting round my (existing) SSD cooler to direct airflow specifically under the PCH heatsink - and then maybe machine some fins in it.

[pointinline]

The PCH temps on my z690 Extreme are right in the 58-59 range at idle. In my computer case, a Corsair 7000D with 11 fans running in quiet mode.

If I set my fans to run in "balance mode" (ups the fans to about 1/4 their rated RPM) this temp goes down to about 54c at idle. Moving cooling air over the rather inefficient heat sink appears to be a more important aspect of keeping it cool than one might normally see.

I'm going to first try a tiny 30mm fan blowing right on the area of the heatsink above the chip. At full RPM, this fan (the same one used in the Maximus XII Extreme is nearly silent even at full RPM, but should produce a nice spot area of fast airflow for carrying away heat.

I'm reminded of the tests that I've seen on youtube of the NZXT GPU cooler bracket accessory which has the cooler affixed only to the GPU with cooling of the memory chips and VRMs provided by a single fan blowing directly on these components and equaling or besting the temps of the cards with the full heat pipe fin stack coolers on them. It appeared that direct airlow over the parts was a better cooling solution than elaborate heatsinks and thermal paste/pads...

[luntik]

I have the same issue, 68 celsius on idle system
Has anyone asked ASUS if it is ok or not

[PM44122]

I have the same issue, 68 celsius on idle system
Has anyone asked ASUS if it is ok or not

I was on a phone call with an Asus employee regarding some questions about the z690 formul. I also asked him about the chipset temperature, he told me that it’s normal for the z690 chipset even up to 90 CelsiusÂ*

[Brigman]

Moving cooling air over the rather inefficient heat sink appears to be a more important aspect of keeping it cool than one might normally see.

Yes, the limited surface area of the heatsink (on the Hero at any rate) plus the presence of the cosmetic applique on its top surface means that it will struggle to naturally dissipate heat without some assistance from forced air cooling.

As per post above I've already got a 40mm Noctua fan blowing down onto an SSD in the M2_3 position - and the top of the PCH HS gets a fair bit of that, with precious little effect. I'm next going to build a shroud/duct that encapuslates the airflow and forces it down under and around the heatsink - and will probably machine some slots/fins in the edge of the HS nearest the SSD to encourage airflow down there too.

@luntik, as per other posts, we've seen comments here from Asus-affiliated members that this sort of temperature is not problematic, but I'm a perfectionist so if I can improve it, I will. Don't feel as though you have to though.

[luntik]

Got you and thank you guys

One more question is about warranty
Does the PCH thermal pad install affect it?

[Z690AusBuilder]

Yes, the limited surface area of the heatsink (on the Hero at any rate) plus the presence of the cosmetic applique on its top surface means that it will struggle to naturally dissipate heat without some assistance from forced air cooling.

As per post above I've already got a 40mm Noctua fan blowing down onto an SSD in the M2_3 position - and the top of the PCH HS gets a fair bit of that, with precious little effect. I'm next going to build a shroud/duct that encapuslates the airflow and forces it down under and around the heatsink - and will probably machine some slots/fins in the edge of the HS nearest the SSD to encourage airflow down there too.

@luntik, as per other posts, we've seen comments here from Asus-affiliated members that this sort of temperature is not problematic, but I'm a perfectionist so if I can improve it, I will. Don't feel as though you have to though.

Hi What thickness of thermal pad did you use ?

[Minaii]

i would like to know that too which Z690AusBuilder asked.
My Formula Chipset is at chilly 92 °c. That is with Thunderbolt enabled, 3 M.2 NVME SSDs + 2 NVME SSD on the hyper m.2 card and 5/6 Sata ports plugged in.
I managed to cool it down a little by lowering the voltage of the chip down to 0.8v and 0.7v like i read in a different post, so now its at 84-86°c depending on its load.

But i do opt to change out the factory thermal pad for a better one.

[Z690AusBuilder]

Hi Minaii

I was getting 92 C but then I removed the cover that you remove to install the M2_2 and M2_3 Drives, I unpluged and removed the RGB panel below that. Doing that exposes the top of the chipset heatsink to the air flow in your case, I also installed a PCIe Slot Fan to promote more air flow across the top of the Chipset Heatsink.
Doing all that lowered the temperature to 72 C

[Brigman]

Hi What thickness of thermal pad did you use ?

1.5mm - altho 1mm might have been enough.