Can This Cool an RTX 3090?

[AlexTheGreatish]

We want to build some water cooled PCs with the RTX 3090, but just how small of a radiator can we use and still have reasonable temps?

 

Buy ASUS ROG Strix RTX 3090 GPU

On Amazon (PAID LINK): https://geni.us/lc5Ku

On Best Buy (PAID LINK): https://shop-links.co/1721650990659551270

On Newegg (PAID LINK): https://geni.us/c7AqSn

 

Buy EK-Quantum Vector Strix RTX 3080/3090 D-RGB

On EK's site at https://lmg.gg/bcqmp

 

Purchases made through some store links may provide some compensation to Linus Media Group.

 

 

 

[SolarNova]

So EK sponsored the rads, so understandable....

But it probably would have been nice to go from a 'rando' 120mm Aluminium rad, to a 420mm Copper Blackice Nemesis GTR (or GTX) rad from Hardware Labs.

And use Noctua NF-A12x25 fans, that way u can run 1600rpm for performance AND relatively low noise.

 

U'd be showing the absolute worst case to the absolute best case scenario then.

 

regardless, it wouldnt have changed the 'overall' takeaway, just woulda been 'better' imo.

 

 

[Senzelian]

Oh wow, I totally didn't expect a single 120mm radiator to be able to cool a 3090!

 

...

 

 

[Luscious]

Radiators come in many more thicknesses than those. Alphacool (the ones I use in my build) make 25mm, 40mm, 60mm and the chunky "Monsta" 80mm thick variety in 120mm and 140mm fan sizes from singles to quads - that's 32 different SKU's for those counting, not including the more obscure 40mm, 60mm, 80mm, 92mm and 180mm fan size models they also have.

 

Yes, Alphacool will sell you a triple 180mm 80mm thick rad - good luck finding a case to fit THAT thicc boi

 

You could make the argument that a single 120mm 80mm thick rad with two reasonable static pressure fans in push/pull can keep any single block in check. Remember that adding thicker radiators increases the coolant volume in the loop - more coolant volume for the same given heat load means lower coolant temperatures... and lower hardware temps. A longer res tube does the same trick too.

 

But if all you're doing is matching 120-times-whatever rads with how many blocks you have to keep "in check" you aren't really getting any better results than air cooling. Unfortunately that's the big difficulty with modern cases - finding a box that can accommodate radiators and fans properly. Plenty will fit a 2x120mm AIO with a single set of fans and that's where their "compatibility" ends. Go thicker than 25mm, push/pull or you want triples/quads and it's a serious struggle finding a case that can truly claim to be water cooling friendly (again RIP CaseLabs). Even trying to fit two AIO (one for the CPU and one for your GPU) gets complicated.

 

In my case (pun intended) I have five blocks cooling the four GPU's (980Ti) and a full mobo block (CPU/VRM/PCH). Coolant flow goes into the mobo block and then splits across the four GPU's. From there it gets cooled by two dual 140mm rads, a single 120mm rad and two triple 120mm rads. All of them are the "Monsta" 80mm thick type. The pump is just a single non-pwm D5 mated to a medium height res I've got set at #4. All the rads are in push/pull using Akasa pwm fans (22 fans total) that I've wired into just three mobo headers using three 8-way pwm splitters. I have a custom fan curve set in software for both normal 60/70F and summer 80/90F temps.

 

None of the above would have been possible without the CaseLabs case that I am using, however. Trying to do this same build today I would seriously struggle finding a case that could make this all work. Case choice is critical for a well done water cooled build.

[NicholasJ]

Hi ! 

 

Thanks for this nice video. I'm currently waiting … a bit (mid december for now…) to be delivered for my 3090 rog strix. As my PC will be always running and computing, having a silent config matters to me, and therefore your test really pleased me to see.

But… i've never done any watercooling, and i fully see all the problems coming (water leaks, connection not at the proper format, inefficient coolant, etc etc… ) and risks that come with such modification (warranty loss, brick the card… ). But i'm ready to give a cautious try.

 

Would you mind to provide a bundle of what to buy (sponsored if you want) in order to use properly this watercooling block ? (which seems to be very nicely made by the way). Would you also recommend to have some specific attention when removing the factory fans and rads ? Any cleaning required ? (how?) Maybe it would be worse to present a bit more in details this part in you video by the way (at least for me), especially for those 3090 which are going to be top of the line for sometime.

 

As a final question, would you recommend to chain the cooling after the CPU ? Seems possible but a bad idea to me…

 

Thanks in advance for your reply, and thanks for the videos anyway.

[whismerhill]

10 hours ago, Luscious said:

Radiators come in many more thicknesses than those. Alphacool (the ones I use in my build) make 25mm, 40mm, 60mm and the chunky "Monsta" 80mm thick variety in 120mm and 140mm fan sizes from singles to quads - that's 32 different SKU's for those counting, not including the more obscure 40mm, 60mm, 80mm, 92mm and 180mm fan size models they also have.

 

Yes, Alphacool will sell you a triple 180mm 80mm thick rad - good luck finding a case to fit THAT thicc boi

 

You could make the argument that a single 120mm 80mm thick rad with two reasonable static pressure fans in push/pull can keep any single block in check. Remember that adding thicker radiators increases the coolant volume in the loop - more coolant volume for the same given heat load means lower coolant temperatures... and lower hardware temps. A longer res tube does the same trick too.

 

But if all you're doing is matching 120-times-whatever rads with how many blocks you have to keep "in check" you aren't really getting any better results than air cooling. Unfortunately that's the big difficulty with modern cases - finding a box that can accommodate radiators and fans properly. Plenty will fit a 2x120mm AIO with a single set of fans and that's where their "compatibility" ends. Go thicker than 25mm, push/pull or you want triples/quads and it's a serious struggle finding a case that can truly claim to be water cooling friendly (again RIP CaseLabs). Even trying to fit two AIO (one for the CPU and one for your GPU) gets complicated.

 

In my case (pun intended) I have five blocks cooling the four GPU's (980Ti) and a full mobo block (CPU/VRM/PCH). Coolant flow goes into the mobo block and then splits across the four GPU's. From there it gets cooled by two dual 140mm rads, a single 120mm rad and two triple 120mm rads. All of them are the "Monsta" 80mm thick type. The pump is just a single non-pwm D5 mated to a medium height res I've got set at #4. All the rads are in push/pull using Akasa pwm fans (22 fans total) that I've wired into just three mobo headers using three 8-way pwm splitters. I have a custom fan curve set in software for both normal 60/70F and summer 80/90F temps.

 

None of the above would have been possible without the CaseLabs case that I am using, however. Trying to do this same build today I would seriously struggle finding a case that could make this all work. Case choice is critical for a well done water cooled build.

I agree, they could at least have added the most common dual 140mm & triple 140 rads to the video while they were at it...

and "more coolant volume for the same given heat load means lower coolant temperatures... and lower hardware temps"
about this, no this is wrong, it just increases the soak time that's all, e.g. the time at which equilibrium of temps will be found after a sufficient lenght of time has passed to heat up all the additional coolant. In general more coolant has a negligible impact toward equilibrium of temps

[SolarNova]

13 hours ago, Luscious said:

Yes, Alphacool will sell you a triple 180mm 80mm thick rad - good luck finding a case to fit THAT thicc boi

Spoiler

240 x 80 Monsta in Push/Pull

ofc its in a Phantek Enthoo Primo so its not exactly a small case lol.

 

Funnily enough u can get 60mm rads that perform better nowadays so there's really no reason to use a Monsta rad.

 

Still, they have 'presence' at the very least.

[Luscious]

19 hours ago, whismerhill said:

and "more coolant volume for the same given heat load means lower coolant temperatures... and lower hardware temps"
about this, no this is wrong, it just increases the soak time that's all, e.g. the time at which equilibrium of temps will be found after a sufficient lenght of time has passed to heat up all the additional coolant. In general more coolant has a negligible impact toward equilibrium of temps

Actually it does, because boiling a 4 quart pot of water on your stove takes much longer that boiling just a small kettle. So trying to keep 500W of CPU/GPU heat cool with over a gallon of coolant versus maybe only 1/4 of that... plus the thicker rads have more surface area as well for the fans to take advantage of. There is relatively little difference in temperature between hot and cold sides because water will equalize, more so because your pump will circulate the entire loop in under a minute and continue recirculating. But water temperature is an important measurement because it impacts your delta - a lower delta is what you want and increasing your coolant volume will lower your water temps closer to whatever your room ambient is, both at load and idle.

 

My example - I can work in a 30C room in the summer with a delta of 15-20C. That puts my water temps at 45-50C under load with my GPU's sitting under 60C and a CPU that never hits 70C. Increasing my fan speeds can improve that, at the expense of noise, while lowering RPM can get me the same performance in cooler times with less noise. Trying to do the same with skinny rads my water temps would hit 60C pretty quick and even with fans on full blast wouldn't be able to keep things cool enough. The less water you have to carry that heat away, the harder it is to do.

 

Another thing - you really don't want to run 60C water through a D5 as it will fail prematurely. I suspect a lot of AIO pump failures also happen because users end up pushing far too high loads to the point where the coolant temp exceeds the pump specs.

[MajorFoley]

What case is that in this video btw? Haven't seen it before.

[AlexTheGreatish]

5 minutes ago, MajorFoley said:

What case is that in this video btw? Haven't seen it before.

O11 D

[MajorFoley]

4 minutes ago, AlexTheGreatish said:

O11 D

Thanks Alex

[LightPusher]

I wish we also got the coolant temperature for each radiator size, It's useful information for people to reference.