XFX 6800XT custom cooling (Why Manufacturers use 3 FANS?)

vlad_8011

n00b
Joined
Oct 13, 2020
Messages
62
Hi.

So i made custom cooling after series of tests for my 6800XT from XFX with NOCTUA NF-S12A PWM CHROMAX.
P_20210806_141838.jpgP_20210806_141848.jpgP_20210806_141856.jpgP_20210806_141903.jpg

This is second Radeon 6800XT which i modded in same manner, previously i did same thing on Red Devil Limited Edition, with worse resoults - card was noisy, as there was audiable airflow through heatsink fins.
With XFX Merc that problem is not existing, which is kind of strange - heatsink is same size, with fins in same distance from each other. Funny thing - whole process was so simple, that even kid would do it - 6 screws and fan connector - done - whole plastic cover with fans was taken off:
226512268_188783153270850_5578119063083793988_n.jpg228807528_990212718423024_8940839796710963346_n.jpg
Then, putting fans on zip-ties with VGA 4pin-4pin PWM adapter from Gelid + noctua fan splitter PWM (which cause some problems, as one part of splitter is only 3 pin, while plug is made for 4 pin) and 4pin PWM extender cable - done:
228791788_559137615101929_7607348642646422166_n.jpg229471849_508347003581532_3322075099536448915_n.jpg
You may think how ugly it is - and so i am. I dont quite understand today FASHION (beacuse thats all that is) of 3 fans and long-as-hell radiators GPUs. In Red Devil with same fan config card was so on quieter than with original fans, while temps were much smaller. In XFX Merc we are talking about ~20 degree difference and (dont have noise meter) much quieter work.
So that screen shows full fan speed and its resoults on noctua fans, before i managed PWM control on GPU (i had to swap splitter extensions with fans, as one had 3 pin and PWM wasnt working despite the fact, both fans are 4 pin PWM)
228818684_817503315803179_98056801261806175_n.jpg
Same setting, same test on original fans (ofcourse dont have screenshot to prove....) had much worse resoults. As you can see from above, i made some undervolting - 970mV, max VRAM freq. 2000MHz, max core clock 2200MHz, default power setting. I made those undervolt to comfortably sit nest to my PC, while original cooler from GPU was mounted.
I dont use hadphones, my ears are very sensitive to PC noise and i couldnt stand how loud was Red Devil and XFX Merc - just beacuse they rather to look good, than work good (that stupid fashion). I watched milion times reviews of that cards, and every noise test was completly out of ***. Before 6800XT Merc i had 6800 (non XT) merc - same noise, so its not that particular example - all thise cards are noisy as hell. Nothing reflect their noises as fans are relatively quiet - except airflow guide through heatsink fins. Small high pressure fans + tight fitted fins = you got noise.
As i proven second time, you dont need extra long heatsink with part of it, extending above PCB lenght with just big hole in it. You dont need 3 fans, from which one is allways louder over time as its smaller. Hell, you dont even need slim fans!
All i respect was XFX addiction to ease of removing (and replacing) fans, beacuse whole heatsink is almost flat, which on Red Devil was nightmare, as there was lot of molded fan cable holders and fans needed to be on extra spacers (rubber ofcourse).

Here is processhow it looked onRed Devil:
168424558_178498260770755_7751039314656928729_n.jpg168699730_3764875636972240_2672126132439476259_n.jpg168291007_476847833364995_7341473011962452726_n.jpg168466912_279650433659147_7163959952856914847_n.jpg168511615_937985693660937_8562718978621248605_n.jpg168356362_440239407046055_6226610641015339273_n.jpg168554771_795873111035112_9188708944461711170_n.jpg168271843_1216327305451682_4078721225282950519_n.jpg168539956_551985269532279_5510939512474910333_n.jpg168345549_1227268157704733_117278297116308908_n.jpg168699730_288375276063277_3377935900592915935_n.jpg168281602_473372607046838_5360076037142214108_n.jpg168456943_274461557514192_6469765893474724033_n.jpg
Unfortunely, Radeons and lots of new RTX 3000 are not possible to mount vertically, not sure why - people say its beacuse heatpipe design (beacuse they are turning right after cold plate, which is common, and was present in GTX 1080TI, which was working properly....), but i'm sure there is more behind it. So i made several tests with fans 2 x 120mm (mounted to proforated PSU shroud) blowing on original cooler, then blowing on naked heatsink (without original fans), then mounted to heatsink in verticall and horizontal position, and only in horizontal position it give great benefit.
Currently Radeon is audiable on 1100+ RPM, which is no need to use, as card keep great temps up to 900RPM while gaming.
 

notarat

2[H]4U
Joined
Mar 28, 2010
Messages
2,390
Very good write-up on what you did. thanks for posting lots of pics of the process as well! Nice job!
 

Nobu

Supreme [H]ardness
Joined
Jun 7, 2007
Messages
7,169
The shroud would be 0.5" taller with fans that thick, so they probably went with thinner fans to save space. Shorter fans need to spin faster to move the same volume of air through a restricted passage, so they probably added fins and a third fan to improve acoustics and cooling performance.

That said, those compromises are certainly not necessary in every case.
 

cybereality

[H]F Junkie
Joined
Mar 22, 2008
Messages
8,789
I have the Merc. The design is why I liked it so much, the shroud and backplate are preem.

And it's been almost silent for me, but I can understand wanting better performance. Nice job.
 

Gattlin

n00b
Joined
Aug 29, 2021
Messages
5
Hi.

So i made custom cooling after series of tests for my 6800XT from XFX with NOCTUA NF-S12A PWM CHROMAX.
View attachment 382197View attachment 382198View attachment 382199View attachment 382200

This is second Radeon 6800XT which i modded in same manner, previously i did same thing on Red Devil Limited Edition, with worse resoults - card was noisy, as there was audiable airflow through heatsink fins.
With XFX Merc that problem is not existing, which is kind of strange - heatsink is same size, with fins in same distance from each other. Funny thing - whole process was so simple, that even kid would do it - 6 screws and fan connector - done - whole plastic cover with fans was taken off:
View attachment 382193View attachment 382194
Then, putting fans on zip-ties with VGA 4pin-4pin PWM adapter from Gelid + noctua fan splitter PWM (which cause some problems, as one part of splitter is only 3 pin, while plug is made for 4 pin) and 4pin PWM extender cable - done:
View attachment 382196View attachment 382195
You may think how ugly it is - and so i am. I dont quite understand today FASHION (beacuse thats all that is) of 3 fans and long-as-hell radiators GPUs. In Red Devil with same fan config card was so on quieter than with original fans, while temps were much smaller. In XFX Merc we are talking about ~20 degree difference and (dont have noise meter) much quieter work.
So that screen shows full fan speed and its resoults on noctua fans, before i managed PWM control on GPU (i had to swap splitter extensions with fans, as one had 3 pin and PWM wasnt working despite the fact, both fans are 4 pin PWM)
View attachment 382192
Same setting, same test on original fans (ofcourse dont have screenshot to prove....) had much worse resoults. As you can see from above, i made some undervolting - 970mV, max VRAM freq. 2000MHz, max core clock 2200MHz, default power setting. I made those undervolt to comfortably sit nest to my PC, while original cooler from GPU was mounted.
I dont use hadphones, my ears are very sensitive to PC noise and i couldnt stand how loud was Red Devil and XFX Merc - just beacuse they rather to look good, than work good (that stupid fashion). I watched milion times reviews of that cards, and every noise test was completly out of ***. Before 6800XT Merc i had 6800 (non XT) merc - same noise, so its not that particular example - all thise cards are noisy as hell. Nothing reflect their noises as fans are relatively quiet - except airflow guide through heatsink fins. Small high pressure fans + tight fitted fins = you got noise.
As i proven second time, you dont need extra long heatsink with part of it, extending above PCB lenght with just big hole in it. You dont need 3 fans, from which one is allways louder over time as its smaller. Hell, you dont even need slim fans!
All i respect was XFX addiction to ease of removing (and replacing) fans, beacuse whole heatsink is almost flat, which on Red Devil was nightmare, as there was lot of molded fan cable holders and fans needed to be on extra spacers (rubber ofcourse).

Here is processhow it looked onRed Devil:
View attachment 382220View attachment 382219View attachment 382218View attachment 382217View attachment 382216View attachment 382215View attachment 382214View attachment 382213View attachment 382212View attachment 382211View attachment 382210View attachment 382209View attachment 382208
Unfortunely, Radeons and lots of new RTX 3000 are not possible to mount vertically, not sure why - people say its beacuse heatpipe design (beacuse they are turning right after cold plate, which is common, and was present in GTX 1080TI, which was working properly....), but i'm sure there is more behind it. So i made several tests with fans 2 x 120mm (mounted to proforated PSU shroud) blowing on original cooler, then blowing on naked heatsink (without original fans), then mounted to heatsink in verticall and horizontal position, and only in horizontal position it give great benefit.
Currently Radeon is audiable on 1100+ RPM, which is no need to use, as card keep great temps up to 900RPM while gaming.
I have a GTX 1080 ti mounted vertically .Right now the temp reads 29c in a 22c ambient but it reaches up to 58c when pushed hard with an aggressive fan profile .
 

pippenainteasy

[H]ard|Gawd
Joined
May 20, 2016
Messages
1,038
I mean you basically did what most people do in mini ITX setups, shorten the shroud and attach aftermarket fans. It often works better than using stock fans + thin intake fans, and instead just have thicker 25mm fans.
 

ChosenUno

[H]ard|Gawd
Joined
Aug 26, 2011
Messages
1,289
The problem with your setup is that it's a 3 to 4 slot design, while most GPU mfgs want dual slot at most.

Have you thought about using slim 120mm instead?
 

Riptide_NVN

2[H]4U
Joined
Mar 1, 2005
Messages
2,057
The problem with your setup is that it's a 3 to 4 slot design, while most GPU mfgs want dual slot at most.
Noticed that too. Thing is huge lol.

That said even my powercolor 5700xt has a 2.5 slot design and my asus tuf 5600xt is a 2.7 slot. Going over 2 slot designs has been a thing for a while now.

I never understood x-fire and sli when those cards would be sandwiched so close together on most motherboards. Unless you're using a blower card it's a recipe for heat problems.
 

vlad_8011

n00b
Joined
Oct 13, 2020
Messages
62
Gattlin - i had same temps with GTX 1080 Ti gaming X Trio - it was very cold GPU, yet pretty quiet - on original fans.
@trandoanhung1991 - i would gain 1-1,5cm clearance, but that wasnt needed in such big case (note motherboard tray is 1,5cm above PSU shroud). Now i'm switched case For SS Alta F1 + RTX 3080 TUF - all my problems are solved ;) But i dont regret this experiment, it works everytime.
 

xx0xx

Gawd
Joined
Oct 20, 2005
Messages
703
Great stuff!

I did something similar with a noisy 750ti that even at minimum RPM (40% apparently is as low as these are 'allowed' to go) had a quite loud hum. I took off the shroud, zip-tied on a noctua fan with a 2-pin fan adapter, and now it is near-silent and runs just as cool at idle and load, if not cooler.
 

WilyKit

Limp Gawd
Joined
Dec 18, 2020
Messages
284
The problem with your setup is that it's a 3 to 4 slot design, while most GPU mfgs want dual slot at most.

Have you thought about using slim 120mm instead?

That’s probably going to change if the reports of 400-450 watt TDP for Ada Lovelace is accurate.
 

vegan

n00b
Joined
Nov 2, 2012
Messages
9
Given the power consumption 3 fans are needed as much as my old R9 Fury which was a 300W card
 

ChosenUno

[H]ard|Gawd
Joined
Aug 26, 2011
Messages
1,289
That’s probably going to change if the reports of 400-450 watt TDP for Ada Lovelace is accurate.

Well, remember PowerColor had a 295x2 Devil 13 air-cooled edition. 3-fan, triple-slot monster that managed to cool a 600W total TDP dual GPU cores, and still managed below 90oC temps. The card was massive at 3kg, so it came bundled with a support jack.
 

WilyKit

Limp Gawd
Joined
Dec 18, 2020
Messages
284
Well, remember PowerColor had a 295x2 Devil 13 air-cooled edition. 3-fan, triple-slot monster that managed to cool a 600W total TDP dual GPU cores, and still managed below 90oC temps. The card was massive at 3kg, so it came bundled with a support jack.

I think part of the problem is the energy density of newer GPUs. It’s easier to pull 600 watts from a larger area than it is to pull it from a more compact area which is what we get as the transistors shrink in size.
 

ChosenUno

[H]ard|Gawd
Joined
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Messages
1,289
I think part of the problem is the energy density of newer GPUs. It’s easier to pull 600 watts from a larger area than it is to pull it from a more compact area which is what we get as the transistors shrink in size.

Oh you mean the dark silicon problem?

I think that'll require a huge rethink in IHS design, it's not gonna be the cooler's problem. We have proven air coolers for GPUs that can dissipate 600W, so the question now becomes how to spread all that heat from the die over to the IHS as efficient as possible. Maybe some application of graphite there might help?
 
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