Water Loop Issue

[SNIPoR]

previously I was running my setup on the following method " Pump > CPU > GPU1> GPU2> RAD> " using T line Fill port ,the Temps were good enough seeing that HD7970 temperature at 36c on load ,


3 days ago I installed the following " Pump+ Res > CPU > Rad1 > GPU1> GPU2 > GPU3 > Rad2" which looks like this




after that the temperature of the cards went 10~15c higher on load , something not right here , any suggestion on this loop to lower the temps back?

I am thinking to add another pump in the loop and share it with the reservoir.


Water Cooling Setup :
Swiftech Apogee HD
2x Black Ice Xtreme 360 Radiator
DD12V-D5 Pump
monsoon d5 dual bay reservoir
3x Swiftech MCW82-7900 GPU Blocks

[Mobsters]

Air in radiator/system? Air does not want to go down in loop.

[SNIPoR]

Air in radiator/system? Air does not want to go down in loop.

no air in the loop.

[Rogue Warrior]

My guess is the third GPU is causing this increase, however it shouldn't be 10-15 degrees higher. I would run the 3 GPU's on their own loop

[SNIPoR]

What do you think on adding one more pump in the same loop , will it work better?

[washu9]

Well, in addition to the 3rd GPU, he added a 2nd 360 radiator.
So the temp increase should be nowhere near 10 deg C.

My guess would be the flow restriction of the 3 GPU blocks that is running in series is killing your flow.
Is there any way you can check flow rate?
Or just check the rpm of the D5 pump if you have one that have monitoring leads.

[SNIPoR]

The pump is OK. But I can tell that the flow rate of the water is lower after installing the second radiator and 3rd gpu.

[Makymaco]

Options :
-Perhaps there is something blocking the flow in one of your waterblock ?
-You can put the rads or the gpu in parallel
-Make 2 loops one with one 1 gpu + cpu and another with the other 2 gpus.
-add one more pump (but check your waterblocks before), it's more secure : redundancy

[MrBean]

My guess is the third GPU is causing this increase, however it shouldn't be 10-15 degrees higher. I would run the 3 GPU's on their own loop

You will never need a second loop for today's modern home gaming computers. Don't even go there.

Anyway OP, I suspect you have a very high flow restriction somewhere, start with testing that....

[kolombo]

Pomp>RES , not good idea . The air will dampf quite enough pomp pressure, i think. Thus entire flow capacity will be awkward.

[Keyzman]

Pump curves are not linear - they are exponential. Meaning that addition of an extra rad can very well cut your flow rate in half (depending on where you were on a pump-head curve). Let alone a rad + extra water block.

Seeing how you've invested so much in your system, I would strongly suggest spending some more and getting a flow-meter. It will make troubleshooting issues like these much easier.

[ZX2Slow]

More pump is needed for that loop.