"KalmX AMD Edition" - RADEON RX 6400 Passive Cooling Mod

[REVOCCASES]

someone on Reddit asked me if I could do something similar like my RTX A2000 Passive Cooling Mod but for AMD... now what could be better suited for a fanless AMD GPU than the very efficient RX6400, delivering GTX 1650 performance at a TBP of just 53W... that said, I can't quite understand why no manufacturer offers fanless options for this card - perhaps it's too much of a niche to make enough profit...



anyways, here comes the mod...

I chose one of the Low Profile RX6400 cards (made by XFX, Powercolor, Sapphire) so that less of the PCB would block natural airflow through the passive cooler



next I machined a coldplate out of 3mm copper... this covers the GPU die & memory chips and will be used for mounting...



the cooler itself will again be an ACCELERO S1 which is solder onto the coldplate with 138C solder paste



first applying the solder paste, clamping it together and then backing the whole thing for a few minutes until the solder melts...





note that the GPU die is about 0.2 ~ 0.3mm higher than the memory chips - to compensate the height difference you need to use some very soft and thin thermal pads or alternatively you can put a good drop of thermal paste on the memory... if you use pads, they really must be very soft because you can't (shouldn't) apply to much mounting pressure...



last but not least, mounting the new passive cooler - I used the springs from the original XFX heatsink, plus four M2.5x8 screws...



and here is the finished mod:

• GPU: XFX RADEON RX 6400 4G
• Cooler: ACCELERO S1 & CNC machined coldplate
• Dimensions: ca. 2 Slots, 135mm height, 220mm long

 

[REVOCCASES]

now lets see how it performs compared to the stock cooler...

1) Stock Cooler, 1h stress test, 20C ambient



2) DIY Passive Cooler, 1h stress test, 20C ambient



I have attached the drawings of the coldplate to this post for the DIY community - it should be compatible with all LP RX6400 cards - enjoy!

If you're not comfortable doing this mod by yourself, I've listed the pre-modded card in the trade section!

 

[robbee]

Super impressive work again, these temperatures are crazy good!

 

[REVOCCASES]

All it takes is a €50 mod to keep this AMD GPU chill and in complete silence | PC Gamer

 

[b_force]

I have the same XFX RX6400 and have been searching around for some custom cooling solutions.

First of all, I think your mod is really incredible!
It also really motivates me to do something similar (although I don't think my CNC is powerful enough)

I have been trying to cool this little card down.
Currently I am using it in a very small build, but unfortunately the little GPU just gets very toasty.

A simple solution would be mounting a 80-120mm on the side, but unfortunately I only have about 10mm clearance.

I don't need to go completely passive, just some better (and more quiet) fan would be better.
I was wondering, would one of those old Zalmen VF700's be good enough?

@REVOCCASES do you have any idea how different the thermal performance would be by making the adapter plate out of aluminum instead? Obviously it's not possible to solder both together anymore at that point.

 

[REVOCCASES]

@REVOCCASES do you have any idea how different the thermal performance would be by making the adapter plate out of aluminum instead? Obviously it's not possible to solder both together anymore at that point.

a 3mm aluminum plate should also be fine if your CNC has trouble with copper... perhaps you could mount the Zalman on it using thermal paste and screws... alternatively you could buy a aluminum heatsink and mod it to make it fit on the RX6400...

 

[b_force]

a 3mm aluminum plate should also be fine if your CNC has trouble with copper... perhaps you could mount the Zalman on it using thermal paste and screws... alternatively you could buy a aluminum heatsink and mod it to make it fit on the RX6400...

Do you think those Zalman heatsinks will be enough to cool the whole thing?
It has been a while, and I can't remember what "TDP" they were using back in the day.
(getting old lol)

I will have a second look on the heatsink design, the PCB requires quite some attention for clearance.
Otherwise some kind of adapter plate would work there as well.

Edit: So I just wanted to show some progress with sobe low profile fan adapters I made. But unfortunately by pulling out the fan adapter board, I accidentally pulled the Rx6400 with it. Now it's not working anymore. (I should have know better I know).

Does anyone know the common fail state when that happens? I find it hard to believe that the gpu I itself us fried.
Worth troubleshooting the issue and maybe replacing some parts otherwise. (I have years of experience in smd soldering and pcb design).

Anyway here is a first proto of the low profile fan adapter. This is with 40mm fans, 60mm would just fit as well (just slighly out of the official design specs)

Edit2: for some reason image won't upload?

https://tweakers.net/i/d9yC0bebn9fKJtyBByoUX1UfZck=/full-fit-in/4920x3264/filters:max_bytes(3145728):no_upscale():strip_icc():fill(white):strip_exif()/f/image/8ipmBpoYISazRhhd810DEpM8.jpg

 

[REVOCCASES]

I guess the Zalman should be sufficient since it's just a 54W GPU

Oh no... sorry to hear that with your RX6400... can you spot any obvious damages / fried components?

Your fan adapter looks really good, nice job!

 

[FlexxRocket]

How did you Get the Threads into the small Copper Plate ? For the 4 screws?
I want to Build a passive Copper heatsink for the rx6400 too.

 

[REVOCCASES]

How did you Get the Threads into the small Copper Plate ? For the 4 screws?
I want to Build a passive Copper heatsink for the rx6400 too.

You'll need a thread cutting tool. You can find some sets ob Amazon or eBay in different sizes.

 

[FlexxRocket]

Ok Thanks! And the Thread size is M2 right?

 

[REVOCCASES]

Can't remember if it was M2 or M2.5

 

[FlexxRocket]

i will Try Soon

 

[FlexxRocket]

Instead of your Accelero S1 i would like to put a Copper heatsink on top of your CNC Copper Plate

https://amzn.eu/d/05G4rPZV

Is this doable or Not possible ?

 

[REVOCCASES]

Instead of your Accelero S1 i would like to put a Copper heatsink on top of your CNC Copper Plate

https://amzn.eu/d/05G4rPZV

Is this doable or Not possible ?

Possible, but not enough to run it passive cooled. You'll need the heatpipes and larger fin surface for passive cooling.

 

[FlexxRocket]

I would Mount 2 Noctua A6x25 on top
Would that be enough?
I want to Design a 3d Printed Case for the Fans on top of the Card
I already ordered the CNC Copper plate Part , so i have to Try it and Look How it turns out

 

[REVOCCASES]

Sure, with active airflow it'll work.

RTX A2000-X3 | a cool&quiet tripple fan mod for the A2000

while I am still enjoying my A2000 single slot mod in the 1L Thinkstation P350 Tiny for daily work, I realized that it gets a little bit too noisy for my taste during gaming... the original NVIDIA cooler works OK-isch but I thought there is still room for improvement... inspired by the...

smallformfactor.net

 

[REVOCCASES]

Edit... just not sure if the caps are in the way... but you can drill some holes in the heatsink in case they're too tall

 

[FlexxRocket]

Ok i will Try this but i think when the heatsink is on top of the 3mm Copper Plate , all the Parts will fit beneath it

 

[FlexxRocket]

i dont know how to attach the copper heatsink to the CNC copper plate. I found a thermal adhesive on amazon. https://amzn.eu/d/037UTEx4
is it able to do the job?.
Also do i have to replace the termal pads for better performance?