CPU/GPU parallel loop help please

D1craig · 15 Aug 2018 at 01:19

im about to perform some maintenance on my loop and i would really appreciate some help in loop design. i want to go from a serial loop to a parallel loop.

evolv itx,
GPU,
CPU,
240mm Radiator (may add in my 120mm),
Pump/Res combo.

currently i run it Pump/Res>GPU>Rad>CPU.

for some reason i just cant work out how to make this parallel rather than serial.

Space Monkey · 15 Aug 2018 at 01:26

Isn't parallel loops for dual GPUs?

Found this link from a while ago, maybe a good starting point?

https://forums.overclockers.co.uk/t...-single-cpu-in-a-parallel-flow-loop.18414278/

bremen1874 · 15 Aug 2018 at 01:26

Why parallel?

D1craig · 15 Aug 2018 at 01:35

bremen1874 said:
Why parallel?

i dont know, sounds like it may be easier to route everything.

bremen1874 · 15 Aug 2018 at 01:43

Unless the resistance of each branch is the same (unlikely) aren't you going to get more water flowing through one side than the other? Not 100% it would matter, but it doesn't feel right.

LuckyBenski · 15 Aug 2018 at 07:36

D1craig said:
i dont know, sounds like it may be easier to route everything.

Series will have the lowest number of tubes and fittings as every component has one input and one output. You're describing a parallel SECTION because to go fully parallel you'd need two pumps and two radiators. At the very least you'd have a radiator after each block in parallel but share a pump.

Do you want to figure out the extra routing? You'll need a way to split the tubing into two at some point, and a way to rejoin them after the parallel section. It will take up more space and have more potential points of failure.

Going parallel puts you at risk of higher flow through one side than the other, but this might be fine. It should be reasonably balanced as water will take the opportunity to flow down both routes as it's less resistance. The pump won't be under any additional load because you've actually made the loop less restrictive.

pastymuncher · 15 Aug 2018 at 08:06

A lot of cpu blocks specifically state that they are not to be used in parallel, mine does. You want the maximum flow through the cpu block to make the most of the jet plate designs that they have these days and the only way to do that is to run in serial.

Radox-0 · 15 Aug 2018 at 14:39

I use a parallel loop in one of my rigs and it works fine. However there is a slight impact to temps compare to serial, as the block's have different resistance (CPU and GPU) and depending on the layout, the water may not go through the CPU block in as high volume. In my parralel loop for example, the flow rate through my CPU block is lower but its sufficient enough that temps remain reasonable if you have a solid pump. (using a DDC pump here for 2 radiators, CPU and GPU and runs at around 40% so pretty inaudible)

If your looking to make it parallel, have the water flow in through the bottom of one GPU hole, the the hole on the otherside go to the CPU. potato picture as follows:

So my parralel loop is in the Shift X, but same premise and looks as follows with parralel loop. Below is back with entry and exit to GPU:

On other side the two ports run off into the CPU like shown:

Shilz · 15 Aug 2018 at 22:42

I run my PC in parallel. Res>rad>GPUs>CPU then back to the top rad and back into the Res. Flow is perfect with a single D5 running at 2k rpm and water temps never max 40c. Currently running this as a mining rig 24/7 for about 6 months with no issues.

Optimal radiator mounting and res will help your parallel build.

Have a look at a few pics here https://forums.overclockers.co.uk/posts/31695813/

D1craig · 15 Aug 2018 at 22:52

thanx for pictures. i changed my mind while thinking about it today. going to just go for serial routing. i know where i am going then. maybe if my case was a little bigger i could do it.

LuckyBenski · 15 Aug 2018 at 22:59

Shilz said:
I run my PC in parallel. Res>rad>GPUs>CPU then back to the top rad and back into the Res. Flow is perfect with a single D5 running at 2k rpm and water temps never max 40c. Currently running this as a mining rig 24/7 for about 6 months with no issues.

Optimal radiator mounting and res will help your parallel build.

Have a look at a few pics here https://forums.overclockers.co.uk/posts/31695813/

Surely that's all parallel?

Shilz · 15 Aug 2018 at 23:10

LuckyBenski said:
Surely that's all parallel?

The water only flows one way around the whole loop. The left output on the bottom GPU goes up to the top rad.

LuckyBenski · 15 Aug 2018 at 23:30

Shilz said:
The water only flows one way around the whole loop. The left output on the bottom GPU goes up to the top rad.

It's still parallel. If the CPU block was in series, its inlet and outlet would both be after the GPU blocks. Of course it only flows one way, it's not alternating current

/electronics nerd

Radox-0 · 15 Aug 2018 at 23:55

LuckyBenski said:
It's still parallel. If the CPU block was in series, its inlet and outlet would both be after the GPU blocks. Of course it only flows one way, it's not alternating current

/electronics nerd

Yup that is a perfect example of a parallel loop. you can bet some of the flow going into the bottom GPU will go right around said GPU block then out again and never go to the second GPU / CPU

ilc72 · 27 Aug 2018 at 18:40

Shilz said:
I run my PC in parallel. Res>rad>GPUs>CPU then back to the top rad and back into the Res. Flow is perfect with a single D5 running at 2k rpm and water temps never max 40c. Currently running this as a mining rig 24/7 for about 6 months with no issues.

Optimal radiator mounting and res will help your parallel build.

Have a look at a few pics here https://forums.overclockers.co.uk/posts/31695813/

That is the most beautiful mining rig I’ve ever seen!