[SOLVED] I need help regarding my Custom GPU water cooling!!

Dec 11, 2021
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I want to watercool my RTX 3090 with an AIO but the issue is the VRMs and Memory need cooling as well.
I have watched some videos where they put small copper heatsinks on said componens(VRM, VRam)but the other issue is what kind of thermal interface material to use(Thermal Pad, Thermal Glue, Thermal Tape)?
Also are small copper heatsinks preferably the ones sold by Alphacool enaugh to cool the Memory and VRMs of an RTX 3090?
I would like to re use a 240mm AIO that I have laying around!
Any help is greatly appreciated!
 
Solution
The memory on these 3xxx cards run hot. You're asking for trouble doing it the way you're trying. As stated above, you need to look into a full waterblock. You have the most expensive GPU on the market right now. Hopefully you can spare a few quid to properly cool it.
What are you trying to accomplish?
Is your 3090 too hot?
What is the rest of your system?
I am trying to fit my 3090 in a 1U(40mm height) chasis but the cooler is too thick, the radiators I will be using are Alphacool NexXxoS UT60 Full Copper X-Flow 40mm Hepta radiator!
I am basically trying to copy DIY PERK's watercooled table PC but mine is going to be mobile meaning I can take it with me anywhere I go!
The rest of my system is:
  • Asrock FATAL1TY B450 itx with 6000s bios update
  • EVGA RTX 3090
  • 32GB Corsair DDR4 2x16 3600
  • 1TB samsung M.2 NVME
  • HP 1200watt Platinum+ server PSU
  • 5TB Barracuda
  • Ryzen 9 5950x and some other accesories 😉

View: https://youtu.be/HhWDPG8EROw
 
Last edited:
I am trying to fit my 3090 in a 1U(40mm height) chasis but the cooler is too thick, the radiators I will be using are Alphacool NexXxoS UT60 Full Copper X-Flow 40mm Hepta radiator!
I am basically trying to copy DIY PERK's watercooled table PC but mine is going to be mobile meaning I can take it with me anywhere I go!
The rest of my system is:
  • Asrock FATAL1TY B450 itx with 6000s bios update
  • EVGA RTX 3090
  • 32GB Corsair DDR4 2x16 3600
  • 1TB samsung M.2 NVME
  • HP 1200watt Platinum+ server PSU
  • 5TB Barracuda
  • Ryzen 9 5950x and some other accesories 😉

View: https://youtu.be/HhWDPG8EROw
You need to buy a water block designed for an RTX3090 that actively cools the memory on the back of the PCB. If your DIY solution does not actively cool the memory on the back of the card, then it is pointless to water cool only one side of the card. Doesn't matter how cold the memory on the top of the card is if the bottom is cooking at 110C and throttling your performance.
 
You need to buy a water block designed for an RTX3090 that actively cools the memory on the back of the PCB. If your DIY solution does not actively cool the memory on the back of the card, then it is pointless to water cool only one side of the card. Doesn't matter how cold the memory on the top of the card is if the bottom is cooking at 110C and throttling your performance.
I will be reusing the original back plate and blasting the area with plenty of cold air!
I know you worry about the back plate not getting enaugh airflow but my design allows for 1.2cm of clearence between the back of the gpu and chasis which my 5- 40mm static pressure noctua fans will be more than happy to cool!
 
The memory on these 3xxx cards run hot. You're asking for trouble doing it the way you're trying. As stated above, you need to look into a full waterblock. You have the most expensive GPU on the market right now. Hopefully you can spare a few quid to properly cool it.
 
Solution
The memory on these 3xxx cards run hot. You're asking for trouble doing it the way you're trying. As stated above, you need to look into a full waterblock. You have the most expensive GPU on the market right now. Hopefully you can spare a few quid to properly cool it.
Well I looked up some dimensions of an actively cooled backplate and block combo but the problem is the card becomes too thick to fit in my 1U case which is excatly 4.3cm and the gpu block combo is 5.4cm which is going to cause it to stick out of my case! 🙁
 
The memory on these 3xxx cards run hot. You're asking for trouble doing it the way you're trying. As stated above, you need to look into a full waterblock. You have the most expensive GPU on the market right now. Hopefully you can spare a few quid to properly cool it.
Oh boy I think I messed up 🙁 I should've gone for the 6900xt that doesn't have those annoying memory modules on the back TOT
Anyway thank you for your time!
 
Not to be a downer here but building "mobile" hardware out of desktop stuff is a recipe for mechanically broken parts. The board headers are not designed to take that kind of mechanical stress and even something as simple as a typical apartment move causes problems all of the time. Water blocking would seem to bring an advantage, but by the time the total mass is figured it isn't far off from the air cooled equivalents, only leverage is reduced some. And if moved around too much it will leak.
 
Well I looked up some dimensions of an actively cooled backplate and block combo but the problem is the card becomes too thick to fit in my 1U case which is excatly 4.3cm and the gpu block combo is 5.4cm which is going to cause it to stick out of my case! 🙁
Without some custom fabrication skills, 1U is too narrow for a properly cooled 3090 with off the shelf cooling solutions.
 
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Not to be a downer here but building "mobile" hardware out of desktop stuff is a recipe for mechanically broken parts. The board headers are not designed to take that kind of mechanical stress and even something as simple as a typical apartment move causes problems all of the time. Water blocking would seem to bring an advantage, but by the time the total mass is figured it isn't far off from the air cooled equivalents, only leverage is reduced some. And if moved around too much it will leak.
I will be using high quality Alphacool parts, they will be shipped to me from Germany!
Everything will be snuggly mounted so there is no wiggle room, as for cooling all I want is slightly better temps if not stock temps are fine as long as I make it fit in a 1U form factor.
 
I will be using high quality Alphacool parts, they will be shipped to me from Germany!
Everything will be snuggly mounted so there is no wiggle room, as for cooling all I want is slightly better temps if not stock temps are fine as long as I make it fit in a 1U form factor.
I hope it works out for you. You are going to want to support that 1U riser and GPU very well. Probably something like hot glue in the right places with custom standout supports. There is a reason when you open up a laptop that everything is in the same plane, as flat as possible to the motherboard and screwed down.
 
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I hope it works out for you. You are going to want to support that 1U riser and GPU very well. Probably something like hot glue in the right places with custom standout supports. There is a reason when you open up a laptop that everything is in the same plane, as flat as possible to the motherboard and screwed down.
I will be using motherboard standoffs so don't worry they will be sitting flat and well mounted since my plan is to use a PCIE cable so the card can lay flat!
Everything I make is mechanically very strong also I never use Hot glue!
Thanks for the reply!