Should I Be Worried? (Router Temp)

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vaynardx

Occasional Visitor
Temps.jpg


So, my router's CPU temperature just breached 101C. It is mostly hot here in the Philippines since it is summertime. Should I be worried about the temps? My router is placed in a position with ample airflow with nothing restricting it. The only settings I've changed are the router radio (wireless) and WAN dns and nothing else. Should I be worried?
 

heysoundude

Very Senior Member
look OUT...It's gonna BLOOOOOOOWWWWwwwwww

Seriously - we need to know what model hardware so we can offer advice. right now, all we can say is to unplug it and let it cool down for a week before plugging it back in

Have you searched for answers here? There are plenty of threads - you'll probably find one for your machine
 

Sanna1967

Senior Member
I bet on AC86

 

vaynardx

Occasional Visitor
Yes, my router is the AC86 and I am on the latest firmware. I think this has happened since the 384 patch. Can anyone tell me what to do to somehow reduce the temperature without relying on external means?
 

Wistuplu

Regular Contributor
without relying on external means
That's a big constraint. Pull the plug ? ;-)

13 pages of ideas here https://www.snbforums.com/threads/router-temperatures.71123/page-12
and in many other threads.

It seems that having many network cables plugged into the router increases the temp. Relying on an external network switch might help reducing temp. This is not first-hand information. I am just reporting something read elsewhere. But I like that it is neat and silent.

My own AC86U runs at 77C in normal room temperature.

I have always been wondering if those with high temp had a faster connection and/or more clients. I guess it takes more energy to push 1Gbps with a lot of actual traffic, instead of limited traffic on a 40Mbps connection.

Best regards
W.
 

Centrifuge

Regular Contributor
what to do to somehow reduce the temperature without relying on external means?
Roll back to the 384 codebase. Here @gattaca talked about turning on/off power saving cpu wait mode etc., you could play around with that, see if it made a difference. Also, let the router settle after going to 386, it does some database processing that can leave the gui unavailable and may also cause the cpu to be more active and therefore hotter.
 

mromero

Senior Member
View attachment 33343

So, my router's CPU temperature just breached 101C. It is mostly hot here in the Philippines since it is summertime. Should I be worried about the temps? My router is placed in a position with ample airflow with nothing restricting it. The only settings I've changed are the router radio (wireless) and WAN dns and nothing else. Should I be worried?
Role back to 384.19 ASAP, put a fan on it, or wait for 386.3 version to see if Asus fixes the overheating issue.
 

RMerlin

Asuswrt-Merlin dev
If your router is breaking 100C, then you have a hardware problem. Hiding it by downgrading to an older firmware will not fix your overheating issue, you need to sort that out. Either make sure there is sufficient airflow, or RMA the device.
 

gattaca

Senior Member
^^^ Without external means - tough to impossible! If your router is out of warranty, then attaching a small fan, as described in detail in several recent threads, blowing onto/into the rear of the router is the most cost-effective solution to lowering the operating temps. If you do not want any "external means" then run it until it fails. Stay safe, stay alive. Peace.

Update: From all the excellent dis-assembly and observations, we know those thermal pads are sub-optimal. ASUS should have done better. I didn't want to go down the "disassembly to fix it deep hole."
 
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RMerlin

Asuswrt-Merlin dev
^^^ Without external means - though to impossible!
I was mostly referring to the basics there. Like people who love to stack their router on top of the modem, which sits on top of a switch, within an enclosed cabinet. Give the poor thing some breathing room.
 

JWoo

Senior Member
This is a HW design issue! Let's call it what it is. This is a router that sits vertically so it has a chimney for cooling; it should in theory run quite cool.

The RF shielding on this router (and many others) creates a depth issue preventing a flat heat sink from directly contacting the CPU, switch, radios and other critical chips. Rather than spending $$$ to machine a fancy heat sink that can contact the chips, the gap between the chip and the heat sink is filled in with thermal pads, which often don't conduct very well.

Below is the RT-AC86U from FCC photos showing the very large thermal pads used as the heat sink cannot directly contact the BCM4906 SoC, or the BCM4365 and BCM4366 radios. The CPU/Switch, and the 2 radios, which generate the majority of heat on the board, are also all sharing a common heat sink.

1619200207464.png


On the back side, Asus did a better job. The metal plate is indexed so there is closer metal to component contact (although thermal pads are still used). I have seen other manufacturers use a metal plate like this on the CPU side and thermally bond a flat heat sink to an indexed metal plate to avoid the use of such big thermal pads.

1619200414208.png
 

JWoo

Senior Member
As an example, here is the Netgear RAX10, which uses the BCM6755 (1.5 GHz, 4 cores) SoC.

The RF shielding is nicely indexed, so the SoC and other chips directly contact the shielding plate:

1619202573123.png


And the flat heat sink thermally bonds to the RF shield without the use of such thick thermal pads.

1619202680289.png


The Asus router equivalent to this one is the RT-AX56U and it does not have nearly as good of a thermal solution as what Netgear did.

Asus needs to get out the WOPR and rework their thermal models.

1619203005173.png
 

kernol

Very Senior Member

Centrifuge

Regular Contributor
Asus needs to get out the WOPR and rework their thermal models.
Maybe ASUS is trying to break into the emerging combo router/space-heater market.
 

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mromero

Senior Member
This router should be recalled or discontinued. It can't operate in up to 40C environment as per Asus specifications.
They borked the design of the Asus RT AC86U. I would not expect a worldwide recall unless something catastrophic happens.
 

heysoundude

Very Senior Member
They borked the design of the Asus RT AC86U. I would not expect a worldwide recall unless something catastrophic happens.
I would expect a firmware update that fries them rather than a recall.
not literally, of course, but they're pushing the AX routers pretty hard so that the AC stuff is artificially obsoleted sooner than later
 

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