RATIONAL custom loop for 14900K and 4080S

[BoggledBeagle]

REVISION 2

I installed EK P280M radiator on the top of the case, the only installation option possible (collisons with roof panel shape and with motherboard) was with one layer of fans on top.

I also installed EK X420M in the front. I had to cut out the lower side of the CD drive mounting bracket, the CD drive still fits!





I tried running the top rad alone exhausting air:



It can handle the heat load 360W, unfortunatelly the GPU temperatures are alredy approaching the temps of good air coolers. Fans at 80% are pretty loud too. I believe this would stabilise as well with fans and pump both at 70%.

Then I added the front rad to the top one, fans and pump at 100, 70 and 50%:






and measured the same with the front rad alone:





The results from above screenshots, compared to my radiator bench measurements:



The 280 rad behaved almost the same as I measured it out of the system on the bench with my water cooldown method, however the rad combination with fans at 100% was cca 25% worse than they performed when they were on the bench, possibly due to the top rad exhausting air using the warm air from the front rad.

You can also see what the PWM rating of the fans and pump corresponds well with the loss of the cooling performance.

When I ordered the performance numbers, here are the results:



The most interesting (for me) combinatios are marked yellow.

X420 rad with fans and pump at 70% (notably noisy) and both rads with fans and pump at 50% (quiet) have the same thermal performance: the water temperature flowing in the GPU and CPU is the same, however the quicker flowing noisier one rad cools the GPU to lower temperature.

The question stands: at what combination of fan and pump speed is the GPU temp the lowest, with given limit for the noise???

I have now only the front large rad in the system, I will see if I get any acceptable combination with it. Having the two rads in the system would make finding this combination much easier though.

When I started writing this post, I was almost certain to use just the front rad alone...

What I learned so far: very good near silent cooling is not easy to achieve with a "normal" system. You probably need specialised PC cases for that.

 

[ThrashZone]

Hi,
Best gpu cooling is hitting it first before the cpu.

EK rad shells around their rads are really a pita making them larger than other same mm size rads.

 

[BoggledBeagle]

EK rad shells around their rads are really a pita making them larger than other same mm size rads.

Yes, I learned it first hand now, the corsair 280 could lay on the top panel just fine, the EK could not fit, it was hitting some pressed in rails on the panel.

Also they have a weird decorative shrouds on the ends. If I wanted to undo the extra plug to bleed some air from the rad, the spilover water will run under the decorative shroud.

 

[ThrashZone]

Hi,
Yeah I just removed chunked a ek 280ce in the garbage from my z490 rig and installed a 280 gtx instead I had in my x299 build I'm parting out.
Way better rad.
I've got it push/ pull on the top part and single fan push on the lower part about all I can do in my little D450 midtower the reservoir in the way.

But I hit the cpu first seeing it's the hottest item.

 

[ThrashZone]

After swapping it out i noticed I had some crap in the cpu block so I cleaned it out
Damn I love clear water blocks hehe

 

[Vya Domus]

I think your biggest bottleneck here is that the front of your case is simply too restrictive. If both rads would get fresh unrestricted air the temps would be a lot better.

 

[ThrashZone]

Hi,
I agree the front is completely blocked and air has to be routed through the side vents
Hope you have that front rad as push/ pull thick rads really do need it.

 

[BoggledBeagle]

I got nearly the same result from the 420 rad measured in the open air and mounted in the case (with the door opened) with 100% fan sped.

On the previous page I wrote that closing the door increased the GPU temps by about 3°C. Closing the door works as dropping the performance of fans set to say 70% to the level of the fans set to something like 62%.

I think I still have some space in the front to add the front push fans there.

 

[BoggledBeagle]

REVISION 3



I added front fans on the rad, they do help to move the air through this thick rad. Unfortunately with some parts of the front case wall too close to the blades, they make a lot of noise, they are unusable for more than 50% speed.

I also redid the loop for the parallel connection of GPU and CPU. The water flow increased considerably and also the GPU temps got worse.

I tried to load both the GPU and CPU, you can see the temps of the components in this screenshot:



More than 500W in the water resulted in 33,5 °C water temp, that is 13,5 over ambient. If I calculated thermal resistance from these values, the result would be incomparable to my previous results, which were with one layer of 100% fans, air flow in this case is a result of different fan setup and automatic regulation.

Then I switched the additional CPU load off and the gaming load is here:



The last hill on the water temp curve is me closing and opening the door of the case.

 

[ThrashZone]

Hi,
Yeah parallel I get a laugh when people do that worthless way of piping gpu/ cpu because gpu ports are to thin to do much of anything but be a straight pass through

That front panel design is just pure shit bottom line.
You just have to pick the best poison pill not sure if it's blue or red though but I'd like toss the front panel

 

[BoggledBeagle]

REVISION 4

Do I really need to cool that 80W CPU with water?!



So far this combination is the most quiet. I also removed front fans from the rad.

With fans only at 1000 RPM I am getting 52°C on the gpu.

 

[ThrashZone]

Hi,
A default configuration 14900k is hardly a 80w cpu
Sure you can play with power limits but then again why have water cooling at all.

 

[ir_cow]

Do I really need to cool that 80W CPU with water?!

80 Watts? More like 300+ under full load.

 

[BoggledBeagle]

Hi,
A default configuration 14900k is hardly a 80w cpu
Sure you can play with power limits but then again why have water cooling at all.

You can get a lot of work from it, even when it is limited to 180W, that is what that small air cooler can handle. You can see in numerous screenshots, that the CPU required with a particular game just 70-80W, while running at 5200 and 4200MHz, while the GPU consumed 280W.

That 420 rad may have some heat load level, which it can handle with some particular fans and mounting situation comfortably, but if you add nearly 100W more, it gets out of its comfort zone.

 

[ir_cow]

And here I'm doing 550 on a single 30mm 360 rad lol

 

[BoggledBeagle]

And here I'm doing 550 on a single 30mm 360 rad lol

Wow, and what water temp are you getting? I measured a thick 360 XR7 rad with Arctic P12 fans running full speed to warm water by 17°C above ambient when loaded with 550W.

 

[ir_cow]

RTX 3090 Ti is around 65c and the 12700K, 80c. It's within spec. Only thing that matters to me.

 

[BoggledBeagle]

You most likely have coolant temp between 20 and 25°C above ambient, you are probably exhausting the air from the case through this rad?

 

[BoggledBeagle]

REVISION 5

It is so easy to work on this loop with soft tubing, I can redo the loop in half an hour, I am having fun!

Anyway, here is a tiny loop with only the P280M rad (I measured that it performs the same as a thick XR7 360). I freed a space in the front of the case, where I mounted the PWM P14 fans, and now I can control these fans with the Core XT controller as well. I can return my hard drives where they belong. Temps in the case are again nice and cool.



With lower heat load 240W, the fans run at 1000 RPM and it is still pretty quiet, the GPU temp is 54°C.



I wonder If I should not make some air duct for the warm air coming from the CPU cooler, so that it does not get sucked in the rad.

 

[ThrashZone]

Hi,
Yep love the custom gpu aio hehe
Did one to didn't last very long once I saw what happened on CB 2024 or blender bmw blend
So when back to water on cpu
:

 

[BoggledBeagle]

love the custom gpu aio hehe

Inno3D makes a GPU with AIO (Ichill Black), it was 32K Czk. This one with the block was 31. My custom AIO - counting only the bits currently in use - costs 9,3K. So my custom AIO must be 9,3 times better than the factory one, which it surely is! Right???

Did one to didn't last very long once I saw what happened on CB 2024 or blender bmw blend
So when back to water on cpu
:View attachment 335222View attachment 335223

Your tubes seem to be thick and floppy. Dont they kink? What are they made of? They are some special brand name tubes?

 

[ThrashZone]

Inno3D makes a GPU with AIO (Ichill Black), it was 32K Czk. This one with the block was 31. My custom AIO - counting only the bits currently in use - costs 9,3K. So my custom AIO must be 9,3 times better than the factory one, which it surely is! Right???


Your tubes seem to be thick and floppy. Dont they kink? What are they made of? They are some special brand name tubes?

Hi,
Modmymods 10-15mm or 3/8-5/8" they are pretty stiff
ModMyMods 3/8" ID x 5/8" OD Flexible PVC Tubing - Crystal Clear (MOD-0003) - 3/8” ID x 5/8” OD Soft Tubing - Tubing ModMyMods.com - PC Watercooling Parts and Accessories

 

[ir_cow]

You most likely have coolant temp between 20 and 25°C above ambient, you are probably exhausting the air from the case through this rad?

Yep, rad on top for exhaust. No idea of the internal water temp. It's not boiling and thats the only important part

 

[ThrashZone]

Yep, rad on top for exhaust. No idea of the internal water temp. It's not boiling and thats the only important part

Hi,
Single rad on top exhaust wouldn't matter because you get clean fresh air from front fans..

Dual rads like one on front 2nd on top I personally wouldn't exhaust on the top rad in this situation I'd have both rads as intake.
I like water temp sensors gpu's make it really easy to add one with at least two extra port plugs to choose from hehe

 

[BoggledBeagle]

What the hell is this?! I looked inside the CPU block...



This block has a double function, is serves as a filter too!