Two Pumps, Single or Dual loop? Hard tubing size

[Gegi]

Hello there LinusTechTIpsForum!

 

I already own a custom cooled pc, however I'm planning to do a few upgrades.

My case will be a Corsair 900d, and my Motherboard will be Asus VIII Formula.

As you might know, the Formula VIII has a preinstalled mosfet block by EK, that's why I chose it.

 

I will have a 480 on top, 480 and 360 on bottom, 120 rear.

I have two EK DDC pumps and reservoirs.

I will be cooling my 6700K and two GTX 1080s or the new Titan Xs.

I'm also planning to watercool my 4x8 Corasir Dominator Platinums.

 

So my question is the following:

Should I create a dual loop system, or connect the pumps in parallel and create a single loop?

 

I have a really good looking idea about putting the reservoirs over the pumps, connecting the reservoirs together, and connecting the pumps together with an Y adapter.

I certainly think it would look awesome, however I'm not sure if the pumps connected together that way would suffer any performance or lifetime issues.

 

Also I'm not sure which size of tubing to choose, the 10/12 or 12/16.

The 900d is a huge case, and I'm not sure if the 10/12 wouldn't look too tiny compared to everything else.

 

I would like to hear your thoughts about this!

 

Thanks, Gegi.

[Ichi]

Dual loop is better I guess, in case there's problem with one of the loop at least you don't have to drain everything.

[Gegi]

I don't really care about draining or possible problems.

I would like a system that performs good and has no problems.

 

I would prefer the two pumps in single loop scenario, but I'd like to know if connecting the two pumps together with an Y adapter would have any issues.

[0ld_Chicken]

Connecting the pumps in parallel vs series will provide flowrate benefits, series will increase the total head pressure. Parallel has less redundancy since if one pump fails there will be another path for the liquid to Take. series will just basically go back to single pump performance if one fails.  You can definitely set them up in parallel though, performance just won't really increase and if one pump dies then performance will decrease significantly

 

https://martinsliquidlab.wordpress.com/2011/04/26/pump-setup-series-vs-parallel/

[Gegi]

Okay, so doing them in parallel is nonsense and gives no benefits at all, so serial it is.

Can I go reservoir -> pump -> reservoir -> pump, do I must go reservoir -> reservoir -> pump -> pump.

 

If I think about it, the first pump pushing coolant to the second reservoir in a closed system would automatically push the coolant to the second pump.

[0ld_Chicken]

21 minutes ago, Gegi said:

Okay, so doing them in parallel is nonsense and gives no benefits at all, so serial it is.

Can I go reservoir -> pump -> reservoir -> pump, do I must go reservoir -> reservoir -> pump -> pump.

 

If I think about it, the first pump pushing coolant to the second reservoir in a closed system would automatically push the coolant to the second pump.

yeah, it will work. I think you'll lose some of the pressure from the first pump but it won't be terrible IMO.  I've currently got 2 tube res and 1 bay res/dual pump combo in my build.  The 2 tube res are next to each other in the middle of the loop and don't give me any issues at all.  You could also just make dual loops although that tends to get expensive quick and has little to no benefits in most scenarios.  My last build was dual loop, mainly for aesthetics though.  Performance was great, but no better than one big loop. 

 

Spoiler

 

edit: also I used 14mm tubing and fittings since I thought 12 was too small and 16 looked too bulky.  1/2" is also a good option for inbetween (its just under 13mm) but make sure to get the right size fitting/tubing since metric/imperial don't play nice together

[Gegi]

Do you think my current pump will be enough for the following build:

 

reservoir -> pump -> 480 -> 360 -> gpu -> gpu(parallel or serial) -> 120 -> mosfet -> cpu -> ram -> 480

 

I just found this so mounting the two pumps next to eachother won't be a problem.

 

I was wondering if I can control my PWM controlled DDC pump with a 3-pin fan controller?

[0ld_Chicken]

That is a lot but as long as they are low restriction rads and blocks you'll probably be ok with just the one but a second definitely wouldn't hurt.  You could add that other pump into the loop but it'll have to be with regular fittings since they don't adapt together in any way.  That will work just fine though.

 

You won't be able to control that pump with a 3 pin controller.  The power is provided via the 4pin "molex" connector on the PSU and the other 4pin fan header controls via the 4th "pwm" pin.  It'd have to be a pwm controller or your motherboard