Did anybody ever disassembled RT-AC56U or RT-AC68U?

[Sky1111]

Guys, did anyone disassembled ever AC56 or AC68? How are the heatsinks mounted and what is the thermal interface between CPU and the heatsink?

This article shows the some pictures, but does not tell what is in-between the CPU and the aluminum heatsink:
http://www.smallnetbuilder.com/wire...32120-inside-story-asus-rt-ac56u-and-rt-ac68u

Reason for question: read this article during mu lunch
http://www.tomshardware.com/reviews/thermal-paste-performance-benchmark,3616.html

and came to conclusion that there is a potential to improve thermals by simply changing the thermal paste between heatsink and CPU... and looks like there is also RF shield which adds thermal resistance... (so there are 2 gaps - between CPU and RF, and then between RF and actual heatsink)

 

[connorm]

Guys, did anyone disassembled ever AC56 or AC68? How are the heatsinks mounted and what is the thermal interface between CPU and the heatsink?

This article shows the some pictures, but does not tell what is in-between the CPU and the aluminum heatsink:
http://www.smallnetbuilder.com/wire...32120-inside-story-asus-rt-ac56u-and-rt-ac68u

Reason for question: read this article during mu lunch
http://www.tomshardware.com/reviews/thermal-paste-performance-benchmark,3616.html

and came to conclusion that there is a potential to improve thermals by simply changing the thermal paste between heatsink and CPU... and looks like there is also RF shield which adds thermal resistance... (so there are 2 gaps - between CPU and RF, and then between RF and actual heatsink)

interesting because i use extremely high quality paste on my laptop and it makes a major dif, i wonder how easy it would be to open up a rt-ac66u and apply my own thermal paste

 

[RMerlin]

Opening the RT-AC56U ain't too bad, I've disassembled mine multiple times. I never took off the heatsink however.

You have to first peel off the label at the back - two screws are hidden behind it. The silver base must also be unclipped and slipped off. After that, it's your typical two-part shell, the front plate being the male part, and the casing itself is female.

 

[Sky1111]

interesting because i use extremely high quality paste on my laptop and it makes a major dif, i wonder how easy it would be to open up a rt-ac66u and apply my own thermal paste

I am curious - what would be your thermal paste of choice?

Today I got a small container of Gelid GS Extreme, planning to try it on my very hot graphics card first...

 

[PrivateJoker]

I am curious - what would be your thermal paste of choice?

Today I got a small container of Gelid GS Extreme, planning to try it on my very hot graphics card first...

On Newegg everyone seems to love Artic Silver 5. I have some on hand for the next time I open up my macbook, I'd like to redo its paste on the heat pipe.

I'm very curious as to the actual physical interface between the chips/RF shield/ & heatsink myself. Here's a picture of the AC56 opened up:

http://www.smallnetbuilder.com/imag...c56u/asus_rtac56u_board_rear_w-o_heatsink.jpg

And you can see the 3 shield pieces removed, and in the same orientation as they lay (ie they are proper side up, and face the correct direction), but I don't have any idea what is the interface, if any, between them and the chips. I don't think it's paste cause I don't see any goo residue on the chips. Also the perimeters around the chip areas seem to be outlined in copper on the IC, I'm guessing the shields make physical contact with those perimeters? Why does only one of the RF shields have a thermal pad on it, on the heat sink side? I'm super curious and can't even speculate...

http://www.smallnetbuilder.com/wire...-wireless-n900-gigabit-router-reviewed-part-1

On the RT-N66U B1 production board you can see two RF shields (I have no idea how the CPU and radios are divvied up under the shields) each shield with a thermal pad, and a massive heatsink over the whole thing.

The two tear downs I've read on the N66 were unable to finesse the RF shields off, maybe they are thermally coupled to the RF shields somehow. But if they were, wouldn't the two radio temps pretty much always be pretty close to each other, since they have a physical/thermal bond (a actually, they are always close on mine )? I remember Merlin saying that they will start limping by design at a certain temp, so maybe it's irrelevant that they share the same heatsink.

I dunno. I'm not seeing in any pictures: thermal paste, copper heatsinks (only anodized aluminum), heat pipes, or fans (except for the prototype N66). That makes me think these things don't have really at the limit heat concerns. To my non-scientific brain it looks like RF noise is the bigger foe in designing the router internals, with thermal concerns coming in after that.

Total armchair quarterback, I honestly know nothing of what I speak.

 

[LocalDude]

Total armchair quarterback, I honestly know nothing of what I speak.

Funny... But I think you might be on to something.

 

[ronan_zj]

I tried N56u, but I couldnt take off the front cover

 

[TonyH]

interesting because i use extremely high quality paste on my laptop and it makes a major dif, i wonder how easy it would be to open up a rt-ac66u and apply my own thermal paste

Hi,
First cpu casing and HS surface should mate air tight perfect. Lapping of either surface is some times necessary if one really wants to make it perfect. Heat transfers from cpu to HS, then HS radiates the heat with the help of air movement by natural convection or forced air by a fan. If HS can't dissipate heat efficiently extreme super high quality whatever paste won't do much, right? Being a lazy man I just drill bunch of holes on the enclosure or install small quiet fan at a right position to help cooling when more cooling is needed.

 

[Sky1111]

Hi,
First cpu casing and HS surface should mate air tight perfect. Lapping of either surface is some times necessary if one really wants to make it perfect. Heat transfers from cpu to HS, then HS radiates the heat with the help of air movement by natural convection or forced air by a fan. If HS can't dissipate heat efficiently extreme super high quality whatever paste won't do much, right? Being a lazy man I just drill bunch of holes on the enclosure or install small quiet fan at a right position to help cooling when more cooling is needed.

A fan is absolutely a must if we are talking about improving thermals, but a fan alone cannot prevent local overheating if the CPU or other hot element is not touching that lousy heatsink correctly... or that "thermal" pad actually insulates rather than transfers the heat ...

 

[thiggins]

Most every product I take apart that uses heatsinks either bonds them permanently to the component (not common) or uses a pre-formed pad. The pad is sticky on both sides. Looks like the ones shown here.

 

[Sky1111]

I'll bet if the measurements used in the cited article are subjected to a statistical analysis, it will show that, except for the obvious outliers, they are all pretty much the same, i.e. all within a degree or two of one another. (and which the author hints at...)

As the author notes, how they are applied can make a difference and should be considered when building devices or PCs.

Summed up, if the cooling gain is only a degree or 3, it is probably not worth the time and fuss to change out a paste. Adding a fan to improve the air exchange within the router box will probably give more bang for one's bucks.

In short - I disagree.

First of all , the delta of 1-3 degrees is seen between good thermal pastes. Compare to the crappy ones - and the delta is higher.

Second, we do not even know if ASUS is using thermal paste - all leads to think that they are using thicker thermal pads which are far more thermally resistive. I have seen it on many GPUs, and I am not impressed on how those pads work... so such change can help to drop temps

When I get AC68U (I am trying to sell my AC56 so I do not want to touch it), I will examine it closer to see if I can improve - and I promise to publish "before" and 'after" results. Looking forward to start a new thread on overclocking AC68U

If your router is not hot to begin with (temps are <55 degrees), then there is absolutely no point of voiding your warranty. But if you are getting into 70 degree zone - regardless of overclocking - then it is something to consider - and of course it is not meant to substitute a much needed fan...