Router temperatures

[Fulch58]

The problem on the AX58U is not the displayed temp of 76°. When the problem occurs, the 76° remain even if i try to cool if with a fan.
The problem is the 2.4 GHz does not work well in that case.
A reboot is not mandatory, a small change in WiFi parameters and the problem disappears instantly.
I also opened the case to replace the thermal pads with copper, but after 3 days I had this problem,witch is not existent on 384.19 firmware.

This problem is not unique to the AX58U, I have the exact same behaviour on an AX56U.
2.4 GHz radio temp reports @ 76°, 5.0 GHz is normal as is the CPU. All 2.4 GHz connected devices show RX/TX speeds of 5/1.

Restarting the wireless service instantly reverts the temp to normal and device connection speeds return to expected values.

It seems like the 2.4GHz radio speed gets throttled in response to a possible erroneous temperature reading, is this a plausible explanation?

 

[clweb]

I think it is a driver problem. Yesterday I had the 2.4Ghz temp. 42°C and the 5GHz was at 59°C. Never seen this before. The fan was blowing, but
the 5Ghz speed was about 1/3 of normal (test in LAN with known devices). After a reboot all was normal again.
In the next days I will revert back to 384.19, a version with no problems during more than 3 months.
I think the high temperatures shown are only a visual display of a malfunction of the WiFi chips, probably caused by a driver bug.

 

[JWoo]

This problem is not unique to the AX58U, I have the exact same behaviour on an AX56U.
2.4 GHz radio temp reports @ 76°, 5.0 GHz is normal as is the CPU. All 2.4 GHz connected devices show RX/TX speeds of 5/1.

Restarting the wireless service instantly reverts the temp to normal and device connection speeds return to expected values.

It seems like the 2.4GHz radio speed gets throttled in response to a possible erroneous temperature reading, is this a plausible explanation?

The RT-AX56U uses the BCM6755 SoC for the 2 radios while the RT-AX58U has separate chips. I have a Netgear WAX204 with the same BCM6755 SoC as the RT-AX56U and have never seen the 2.4Ghz wireless cutting in and out; the Netgear does have a much better heat sink solution than the RT-AX56U although the Asus firmware is much better.

 

[Kendo]

Today positioned a 12cm silent cooler in the back of the AC68U, luckily is not noisy at all and it also gives a little blue glow for the router.
Thought it might get the temps down with a couple of degrees.
The results were pretty surprising.
Until now it was like this 50 C - 53 C and 71 C.
Well, I guess it was a good idea.
Now it's time to arrange the cables and find the best position for the cooler...

This picture captured the original temps and the new temps with the silent cooling.

 

[hiewliwen]

Downgraded to 384.19 as well. Hopefully ASUS fixed their side of the firmware.

 

[Kees17760]

Downgraded to 384.19 as well. Hopefully ASUS fixed their side of the firmware.

Did that weeks ago.
I see no point in upgrading. Despite all the fine work of Merlin, 386 brings more Asus cr.p, more power consumption, more generated heat, more instability.

 

[JWoo]

It is surprising that a SW build, in the absence of increased CPU load, can cause an increase in power consumption and heat. For good or bad, Asus has upped their code base to 386 and all future development is on the 386 base.

 

[Tech9]

It is surprising that a SW build, in the absence of increased CPU load, can cause an increase in power consumption and heat.

Not surprising when the router is built with minimum required cooling, keeping the CPU just 20C below thermal protection in idle.

 

[Centrifuge]

Not surprising when the router is built with minimum required cooling

When I got my AC86U in Sept. 2017, it was the envy of ASUS fandom and deservedly, now it's the elephant in the room nobody wants to hear about. It's like they throttled it well past the warranty period and then came out with a new line of mulitcore routers and released the buggy 386 codebase and then wham problems with heat, problems with wifi etc, etc.,. Why some are experiencing problems and others are not, who knows. I have a problem with products that become less good with updates, so I stuck it in AP mode on what I think is peak Merlin for it, and parked it behind an opensource firewall appliance.

 

[gattaca]

^^^ The root issue is all about engineering vs cost/assembly/warranty tradeoffs. I'll explain some of the decision making which goes any manufactured device for those that want a few details for how the electronics industry works. If that's not interesting, then skip the rest of this post.

I'd bet there an engineering report somewhere explaining the potential thermal issues with every option - as engineers do with any ASUS router design. Ultimately what's implemented becomes a MGT decision on cost vs. RASW (reliability, availability, serviceability, and warranty claims.) We see this all the time in every product made. Firms shave a few pennies here and there which adds up to big $ over thousands and thousands of units and while it sounds crazy, adding a quarter to make a better heat-sink can be significant.

FWIW, I own 3 x AC86U units made in 2018. At that time, the AC86U was one of the best performing, most cost effective routers, in ASUS's line! We could play the hindsight is 20/20 game but no point really as we know what we have to do if we want to make these units run as long as possible. This is still a good unit but it has been superceded by newer models.... which BTW, could be improved designs or not. I've seen no teardowns from owners on assembly, only limited FCC photos.

All of my AC86U units are running well - though I have always deployed my routers with small fans for years and well before some of the latest firmware released magnified the thermal challenges with "heat-transfer pad" designs. I've posted on several other threads photos and the graphs as have many others in how they solved this challenge.

My gut says (and years of electronics experience) when we add a small fan as described in several threads, and clean them periodically, adding even a small amount of air into the rear of these routers (or any router or other electronic device which "heats up") extends the life of the unit's components and the life of the unit. This is true not only with routers. Heat is an enemy of electronics, especially electrolytic capacitors and other heat-sensitive parts. There are good, better and best designs and parts. Mgt typically decides that too based on final parts/assembly costs + warranty costs vs expected revenue and profit. In some early designs, you might even see small fans, but that cost tradeoff comes into play and fans = more maintenance, more noise, more expenses. ... , ...., ...., ....

At this point, we, the owners of many great ASUS routers know how to make these run cooler and extend their useful life.

Should we have to add fans to a fanless design to get the performance and life out of it was promised in the warranty? I'll leave that dog sleeping. What we can do at this point is choose to make these good little routers run as long as we can with a few surgical modifications and/or adding fans or we can choose to do nothing and run it until fails and then just buy a new one when it dies probably sooner than it should have. This is true of any electronic device made today = planned obsolesce. As a consumer, I don't always like it, but I do understand what's being done and why. Stay safe, stay alive. Peace.

 

[Kendo]

^^ Well said sir.

p.s. would gladly upgrade my AC68U to AC86U.

 

[heysoundude]

^^^ The root issue is all about engineering vs cost/assembly/warranty tradeoffs. I'll explain some of the decision making which goes any manufactured device for those that want a few details for how the electronics industry works. If that's not interesting, then skip the rest of this post.

I'd bet there an engineering report somewhere explaining the potential thermal issues with every option - as engineers do with any ASUS router design. Ultimately what's implemented becomes a MGT decision on cost vs. RASW (reliability, availability, serviceability, and warranty claims.) We see this all the time in every product made. Firms shave a few pennies here and there which adds up to big $ over thousands and thousands of units and while it sounds crazy, adding a quarter to make a better heat-sink can be significant.

FWIW, I own 3 x AC86U units made in 2018. At that time, the AC86U was one of the best performing, most cost effective routers, in ASUS's line! We could play the hindsight is 20/20 game but no point really as we know what we have to do if we want to make these units run as long as possible. This is still a good unit but it has been superceded by newer models.... which BTW, could be improved designs or not. I've seen no teardowns from owners on assembly, only limited FCC photos.

All of my AC86U units are running well - though I have always deployed my routers with small fans for years and well before some of the latest firmware released magnified the thermal challenges with "heat-transfer pad" designs. I've posted on several other threads photos and the graphs as have many others in how they solved this challenge.

My gut says (and years of electronics experience) when we add a small fan as described in several threads, and clean them periodically, adding even a small amount of air into the rear of these routers (or any router or other electronic device which "heats up") extends the life of the unit's components and the life of the unit. This is true not only with routers. Heat is an enemy of electronics, especially electrolytic capacitors and other heat-sensitive parts. There are good, better and best designs and parts. Mgt typically decides that too based on final parts/assembly costs + warranty costs vs expected revenue and profit. In some early designs, you might even see small fans, but that cost tradeoff comes into play and fans = more maintenance, more noise, more expenses. ... , ...., ...., ....

At this point, we, the owners of many great ASUS routers know how to make these run cooler and extend their useful life.

Should we have to add fans to a fanless design to get the performance and life out of it was promised in the warranty? I'll leave that dog sleeping. What we can do at this point is choose to make these good little routers run as long as we can with a few surgical modifications and/or adding fans or we can choose to do nothing and run it until fails and then just buy a new one when it dies probably sooner than it should have. This is true of any electronic device made today = planned obsolesce. As a consumer, I don't always like it, but I do understand what's being done and why. Stay safe, stay alive. Peace.

Absolutely, people need to incorporate into their thought process regarding these routers: they're meant to become obsolete.
Asus is a hardware company- if their stuff didn't wear out and break down over time, their company wouldn't last very long. perhaps some of the problem is that while other aspects of life in this world are at a virtual standstill, progress grinds ahead in this one.
the people holding on to ac68 machines - those are grandparents (2 generations old) and they eventually have to stop being supported and burn out with the last firmware update, as will the ac86, and the first ax models when wifi6e is fully baked. this is the progression, the natural order.

 

[JWoo]

Disagree. Typically with consumer routers

Absolutely, people need to incorporate into their thought process regarding these routers: they're meant to become obsolete.
Asus is a hardware company- if their stuff didn't wear out and break down over time, their company wouldn't last very long. perhaps some of the problem is that while other aspects of life in this world are at a virtual standstill, progress grinds ahead in this one.
the people holding on to ac68 machines - those are grandparents (2 generations old) and they eventually have to stop being supported and burn out with the last firmware update, as will the ac86, and the first ax models when wifi6e is fully baked. this is the progression, the natural order.

With consumer routers, keep in mind that the manufacturers are on the technology cycle of the chip makers (Broadcom, Qualcomm, Mediatek) plus standards bodies. The router manufacturers don't themselves influence the cycle very much. The chipsets are designed with an MTBF (or FIT) that typically well exceeds the technology cycle. That MTBF is dependent though on the router manufacturer having a proper thermal solution, and the chipset manufacturer will provide the router manufacturer with standard board designs, thermal requirements, device drivers, specs, etc. Also keep in mind that with consumer routers, many if not most of our connected devices at home cannot use the newer standards, so people tend to hang onto their routers for a long time. In the case of Asus, they mostly use Broadcom chipsets. So if Broadcom lays an egg, Asus also lays an egg. With some of these newer chipsets, like the Broadcom BCM6750, I would love to be a fly on the wall listening to the discussion between Asus and Broadcom. Broadcom does not seem to post their MTBF (FIT) data.

 

[Hazel]

the people holding on to ac68 machines - those are grandparents

Did you just call me a 'grandparent'? I'm 46 FFS...

 

[heysoundude]

Did you just call me a 'grandparent'? I'm 46 FFS...

I'm a couple years ahead of you...and yes, we could be grandparents.

 

[Hazel]

With an emphasis on

we could be grandparents

 

[Kendo]

Did you just call me a 'grandparent'? I'm 46 FFS...

Nice one.

 

[heysoundude]

With an emphasis on

HUGE emphasis...massive. gi-freaking-normous.

 

[jerry6]

I J use a 140mm fan sitting on the vent holes of my rt 5300 it runs at 70 C-75 C without the fan DOWN TO 48C - 52 C with the fan . Not that i consider 75c hot it's i just like to keep things as cool as possible sure can't hurt inthe long run .. IF it were running in the 90's I'd look for a solution , 90 c+ I consider high no matter what the chip is rated for

 

[JR Godwin]

On an AX-86......and had the higher temps with the new firmware.....here's an example of what was "normal"...

May 6 12:00:05 RT-AX86U-B330 tempmon[19515]: Logperiod - CPUnow: 72.8C CPUavg: 72.6C CPUhigh: 75.3C CPUlow: 71.8C
May 6 12:00:05 RT-AX86U-B330 tempmon[19515]: Alltime - CPUhigh: 82.6C CPUlow: 65.0C Avg of last 816 averages: 72.5C
May 6 12:00:05 RT-AX86U-B330 tempmon[19515]: LogPeriod: 30m PollFreq: 5s Logged/Expected: 360/360
May 6 12:00:05 RT-AX86U-B330 tempmon[19515]: Current Monitor PID 4572 Monitor Uptime: 2 day(s) 15 hr(s) 53 min(s) 56 sec(s)

Now, I have the alltimes saving on usb to retain.... (so it's a bit outside of Tempmon's normal usage)

At about 1215, I attached this cooling attachment

Cooling Fan from Amazon

and here was the 1230 reading....

May 6 12:30:05 RT-AX86U-B330 tempmon[3462]: Logperiod - CPUnow: 46.8C CPUavg: 60.0C CPUhigh: 72.8C CPUlow: 46.3C
May 6 12:30:05 RT-AX86U-B330 tempmon[3462]: Alltime - CPUhigh: 82.6C CPUlow: 46.3C Avg of last 817 averages: 72.5C
May 6 12:30:05 RT-AX86U-B330 tempmon[3462]: LogPeriod: 30m PollFreq: 5s Logged/Expected: 360/360
May 6 12:30:05 RT-AX86U-B330 tempmon[3462]: Current Monitor PID 4572 Monitor Uptime: 2 day(s) 16 hr(s) 23 min(s) 56 sec(s)

So the next reading will be a period where the fan has been active the whole monitoring period.....

The device itself is very quiet....I'm sitting about 5 feet from it and can't really hear it (but if I get in closer I can, but even then it's quiet)

Before the fan, the room temp in terms of that low / high of 65 and 82 was ranging from 15 to 26

Current ambient temp is about 21, in relation to the cpu temp of 46.....radios are 34 and 37.....previously there were in the high 40's, low 50's.