AC86U overheats with fw 386

[ATLga]

From the official Asus site, Version 9.0.0.4.386.41994 beta is "Please be noted this is a quick fix beta version for DNSmasq vulnerabilities." No mention whatsoever about the overheating issue of the RT-AC86U router.

AC86U overheats with fw 386

I assume the CPU is getting hotter because it is doing more processing, has there been any definitive explanation of what extra processing is taking place, especially if Trend Micro is disabled? I disabled everything to bring the temperature down and CPU was idling most of the time but that...

www.snbforums.com

 

[bbunge]

From the official Asus site, Version 9.0.0.4.386.41994 beta is "Please be noted this is a quick fix beta version for DNSmasq vulnerabilities." No mention whatsoever about the overheating issue of the RT-AC86U router.

41994 beta fixes it.

 

[ATLga]

41994 beta fixes it.

41700 fixed it

 

[maxbraketorque]

9.0.0.4.386_41994-g769f84f
79C in a 20C room - no fan

It appears that many of the people who are seeing 90+C temperatures have their routers in higher humidity environments.

 

[bbunge]

It appears that many of the people who are seeing 90+C temperatures have their routers in higher humidity environments.

Sorry but high humidity has no significant effect on non living objects. Animals yes, blobs of metal and plastic, no. Ok, so changes in air density due to high humidity can effect air flow but high ambient temperature is the killer.

 

[maxbraketorque]

Sorry but high humidity has no significant effect on non living objects. Animals yes, blobs of metal and plastic, no. Ok, so changes in air density due to high humidity can effect air flow but high ambient temperature is the killer.

ok. Perhaps there is a temperature correlation because the only places I've ever been that have high humidity are warm places.

 

[OzarkEdge]

Sorry but high humidity has no significant effect on non living objects. Animals yes, blobs of metal and plastic, no. Ok, so changes in air density due to high humidity can effect air flow but high ambient temperature is the killer.

Varying the water content in air can change its thermal properties, affecting the heat transfer from a warmer material such as a heat sink. You will often see operating humidity conditions list in the specs for equipment... non-living objects:

Environmental
Temperature
▪ Operating Temperature conditions: 0 to 50 degrees C
▪ Non-Operating Temperature conditions: -20 to 70 degrees C
Humidity
▪ Operating Humidity conditions: 20% to 80% non-condensing
▪ Non-Operating Humidity conditions: 5% to 95% non-condensing

5637-ds.pdf (usr.com)

OE

 

[TonyK132]

Just to add my 2¢, I have the dual fan setup from Amazon for $10 on the back of my ac86u that are plugged into the USB port. My temps are: 43C, 49C, 47C. But I'm not running unbound, although I got the fans so I could run it without a temp problem.

 

[dh99999]

I was running Merlin 386.1_2 (95 degrees celcius) and had to revert to Merlin 384.19 (83 degrees celcius) -> these temps are for an ambient of around 26 degrees plus high humidity (90%). Resetting/etc did not resolve the issue.

Merlin 386.1_2 is based on 41700, so I am trying to understand if the changes you are seeing in 41994 are also supposed to be in 41700 (and hence Merlin 386.1_2).

If they are, then I'll probably revert to stock 41994 for a while to test it to see if its something Merlin specific.

So after running stock 41994 for a while, I can confirm:

- Stock 41994 is equivalent to running Merlin 386.1_2 from a temperature point of view
- Both run at least 6-8 degrees hotter than Merlin 384.19 when routers are basically idling (< 10% CPU)
- Running without QOS / AI / Apps Analysis drops the temperature by about 2 degrees (I assume as the CPU has less to do)
- No number of hard resets / soft resets and resetting the router up from scratch made any difference to temperatures

I am back on 384.19 now and will likely stay there until the next ASUS firmware upgrade (or I give in a buy a fan!).

 

[bbunge]

So after running stock 41994 for a while, I can confirm:

- Stock 41994 is equivalent to running Merlin 386.1_2 from a temperature point of view
- Both run at least 6-8 degrees hotter than Merlin 384.19 when routers are basically idling (< 10% CPU)
- Running without QOS / AI / Apps Analysis drops the temperature by about 2 degrees (I assume as the CPU has less to do)
- No number of hard resets / soft resets and resetting the router up from scratch made any difference to temperatures

I am back on 384.19 now and will likely stay there until the next ASUS firmware upgrade (or I give in a buy a fan!).

If you are running 384.19 you may want to disable DNSSEC. That is where part of the dnsmasq vulnerabilities resided that were patched in recent firmware releases.
You will not damage the router with a 6-8 degree C rise. Security wise you will be better off with the newer firmware.

 

[mromero]

So after running stock 41994 for a while, I can confirm:

- Stock 41994 is equivalent to running Merlin 386.1_2 from a temperature point of view
- Both run at least 6-8 degrees hotter than Merlin 384.19 when routers are basically idling (< 10% CPU)
- Running without QOS / AI / Apps Analysis drops the temperature by about 2 degrees (I assume as the CPU has less to do)
- No number of hard resets / soft resets and resetting the router up from scratch made any difference to temperatures

I am back on 384.19 now and will likely stay there until the next ASUS firmware upgrade (or I give in a buy a fan!).

Thank you for confirming my experience. The overheating 386.1 release is in Asus' ball court to fix!

 

[dh99999]

If you are running 384.19 you may want to disable DNSSEC. That is where part of the dnsmasq vulnerabilities resided that were patched in recent firmware releases.
You will not damage the router with a 6-8 degree C rise. Security wise you will be better off with the newer firmware.

Yeah thanks - not running DNSSEC, so thats all good.

That 6-8 degrees is at ambient 25 degrees and low humidity.

The other day, with ambient 26 and high humidity, my temperatures were getting over 95 degrees - a rise of 12 degrees from 386.1_2 to 384.19 - and way too close to it derating for my comfort.

ASUS need to sort this out...

 

[dh99999]

Interesting note from Wade Coxon in:

Release - Asuswrt-Merlin 386.1 is now available

386-1.2 working well on my rt5300 no problems or strange happenings over the last 10 hours . thanks again for the FW

www.snbforums.com

If you are using more than a single Ethernet port on the ac86u, then you will find that they can actually generate a bit of heat, and the last update disabled "Energy Efficient Ethernet".
You can switch that back on by running the following command.
pwrctl config --eee on

That setting should drop the temps a further 5 degrees or so. You will need to add that to a startup script so that it is re-enabled after a reboot.

I haven't tried it yet, but is probably worth checking out.

 

[OzarkEdge]

I haven't tried it yet, but is probably worth checking out.

I don't think so. Why second guess Asus' decision to release it as it is? If the CPU is not throttling, just use it.

OE

 

[dh99999]

Has anyone tried Merlin 386.2 beta to see if it has any impact on the temperature issues?

(It is based on stock 386_42095, so if ASUS have tweaked anything under the covers we may see it appear with this release)

 

[Matthew Patrick]

Mine. AC86U is still higher than 384.19 . Used to be about 68C to 70C on the cool side and only going to 80c on the high side. But since this it's usually on 80C and going to 90C on the high side. On idle to medium usage . But if I do a cpu intensive tasks, it'll go to 95C so yeah I'm buying a fan right now for it. It's supposed to be filtered or whatever. It's quite cheap so if it's unclean-able after a year of dust in the included filter, I could just buy a new one..

 

[Tech9]

Hey guys, I posted some observations about this router in another thread.

Router temperatures

yes, and even the slightest bit helps. I had wired a 120mm 12v fan to a usb plug and taped it on my 86U and got 66C temperatures. This last time, I just set it standing on its edge about 4 to 5 inches away, not "pointed" at the chip, just towards the router, and that got me the same 66C temps...

www.snbforums.com

 

[mromero]

Hey guys, I posted some observations about this router in another thread.

Router temperatures

yes, and even the slightest bit helps. I had wired a 120mm 12v fan to a usb plug and taped it on my 86U and got 66C temperatures. This last time, I just set it standing on its edge about 4 to 5 inches away, not "pointed" at the chip, just towards the router, and that got me the same 66C temps...

www.snbforums.com

I was researching the copper heatsink hack for the ASUS RT AC 86u and came across this mod: https://www.aliexpress.com/item/32910383471.html

 

[Squall Leonhart]

I was researching the copper heatsink hack for the ASUS RT AC 86u and came across this mod: https://www.aliexpress.com/item/32910383471.html

that mod ignores the thermal properties of copper

it absorbs heat faster than aluminium, but under passive cooling it is an insulator, not a dissipator.