Dual loop or Serial & Parallel

[cliffy]

Hi guys, looking for a little advice. Just planning my set up for my Lian Li V3000 rig. Going to be cooling my 3900X and 1080GTX (will upgrade possibly to Ampere later this year)

Radiators wilol be 2*480mm Corsair XR7 Rads (open to advice if there is a better oiption)
CPU and GFX blocks are both EK

I have 2 resevoirs and 2 D5 pumps. Should i ...

Run 2 seperate loops
Run pumps in serial and cool CPU and GFX in parallel (really like the aesthetics of this)

Any advice would be fantastic.

 

[LuckyBenski]

Standard fluid dynamics state that the amount of flow is the sum of all parallel paths leading in/out.

In other words, if you want "normal" flow rates through your CPU and GPU blocks, you will need double the flow rate in the tubes feeding and returning from those blocks.

Running pumps in parallel increases flow rate (they add up their flow). Running pumps in series increases head pressure (they add up their "strength" to push water).

Parallel blocks have lower resistance than series so running your pumps in series won't offer you an immediate benefit. However, you will have redundancy in case a pump fails. There are people who consider 2 pumps in series a sensible choice for safety.

It's a simple loop - I think D5s have the flow rate headroom to handle this if you're set on the look. It would be several extra fittings to split and combine your tubing though.

The benefit of two loops is that you can use different colour coolants. The downside is it's double the probability a pump will fail, and double the maintenance.

You have a lot of choice but I would suggest you plan out your tubing runs and estimate fittings cost/complexity for any layout you want.

 

[cliffy]

Thanks for the reply, i am already running a loop with a single res and pump but want to make the most of the extra room in the lian li case. I guess its going to be about balancing aesthetics with performance. Thanks for the info though was very useful

 

[Jay85]

Standard fluid dynamics state that the amount of flow is the sum of all parallel paths leading in/out.

In other words, if you want "normal" flow rates through your CPU and GPU blocks, you will need double the flow rate in the tubes feeding and returning from those blocks.

Running pumps in parallel increases flow rate (they add up their flow). Running pumps in series increases head pressure (they add up their "strength" to push water).

Parallel blocks have lower resistance than series so running your pumps in series won't offer you an immediate benefit. However, you will have redundancy in case a pump fails. There are people who consider 2 pumps in series a sensible choice for safety.

It's a simple loop - I think D5s have the flow rate headroom to handle this if you're set on the look. It would be several extra fittings to split and combine your tubing though.

The benefit of two loops is that you can use different colour coolants. The downside is it's double the probability a pump will fail, and double the maintenance.

You have a lot of choice but I would suggest you plan out your tubing runs and estimate fittings cost/complexity for any layout you want.

Bloody well explained mate! Good info.

 

[Mcnumpty2323]

Personally I use 2 pumps with the 2nd for redundancy to save the down time should a pump fail ~touch wood but not happened yet
I also used quick disconnects so should a pump fail or want cpu or gpu out can do it with no draining required
Also really recommend x flow/Cross flow radiators with multiple ports
Going in one end out other end of rad leads to less long tube runs and looks a lot neater in my opinion any way

 

[cliffy]

I think i may of got myself confused. Was thinking of using singularity computer res pump combos so it would be
RES1 to Pump 1 to Res 2 to pump 2
Struggling to get my head around it but would the first pump feeding the second res not loose the pressure when entering the res.

Not even sure i am maing sense to myself now

 

[LuckyBenski]

I think i may of got myself confused. Was thinking of using singularity computer res pump combos so it would be
RES1 to Pump 1 to Res 2 to pump 2
Struggling to get my head around it but would the first pump feeding the second res not loose the pressure when entering the res.

Not even sure i am maing sense to myself now

Hmm think of it this way - the "out" pump is pulling water out of its reservoir which is fed by the "in" pump behind it.

The "in" pump therefore does hardly any work to make sure its flow leaves the outlet.

Its hard to picture how that adds much pressure. I don't think you end up with double the pressure, more that the pumps do less work/are under less strain. Not sure how different it is with 2 reservoirs compared to a pump top that places the pumps in series end to end.

Bloody well explained mate! Good info.

Thanks, got a bit carried away writing on the bus to work

 

[MikeTimbers]

Pump A pulling from its A reservoir and pushing to pump B's reservoir.
Pump B pulling from its B reservoir and pushing (around the loop) to pump A's reservoir.

I honestly can't see the point.

 

[malfunkshun]

If you have two pumps and 2 reservoirs and two radiators you may as well do two discrete loops, they'll be thermally independent and you could colour them differently (were you so inclined).
Or, you could use one reservoir and feed two loops that are otherwise separate, but you'd lose the thermal separation of those loops.
Personally I would do the former, or perhaps I would make a single loop with a single reservoir and serial pumps.
Oh, and, if you put a reservoir anywhere other than immediately before the pump(s) you lose pretty much all the performance.

 

[cliffy]

Yeah I’m gonna go dual loop. I have no idea what I was thinking previously. Going to blame that on man flu

 

[Smffy]

Pump to pump for functional gain, dual loop for ‘that looks cool’. Your choice