How do GPU Loops like this one work?

[Ashihtaka]

I've been seeing many builds recently where the tubing goes through one side of GPU into CPU and out the other side.
For example, this build from JayzTwoCents here.

How does the GPU receive enough cooling this way? I would assume from the pump it goes straight through to CPU and then back out to the radiator with only a trickle of water going into the GPUs.
Anyone able to explain how this is cooling the GPUs sufficiently?
Or is the entire premise of this type of parallel loop to have better aesthetics for lower cooling efficiency in GPU?

[warplane95]

Go at 4:55, you can see the flow in the waterblock.

[DazMode]

Liquid flows pass of less resistance, so block with lesser resistanse will get better flow. I personally avoid parallel setups, but many use without ill effect.

[Hooded]

This is called a parallel configuration.
It uses the back pressure that exists in the CPU block to create flow through the GPU blocks. The GPU blocks have less back pressure but equal resistance. So the flow passing through the blocks is slowed, but still sufficient enough to allow heat transfer.

[Ashihtaka]

So with less flow to GPUs, I assume overall cooling performance for GPUs is worse in parallel configurations compared to serial

[10e]

I've done both serial and parallel and not seen much difference in cooling performance. Most GPU blocks are not very flow sensitive, and do not require high flow to do their work unlike some of the more restrictive CPU blocks.

[Bartacus]

I think a lot of us have done both serial and parallel for GPUs, but most of us never include the CPU in the parallel loop like Jay did. I've only done GPUs, but like everyone else said, I noticed no performance difference from a serial setup.

[Hooded]

If GPUs are in parallel and CPU in serial you get great flow through GPU blocks.
However if you include your CPU block in the parallel loop as Jay has done then the temps on everything will most likely be a little higher.

[Ashihtaka]

If GPUs are in parallel and CPU in serial you get great flow through GPU blocks.
However if you include your CPU block in the parallel loop as Jay has done then the temps on everything will most likely be a little higher.

I was wondering if this may be the case as well. Seems like a lot of conflicting opinions on the net right now, I might test this out myself and see if there are any noticeable differences in temp/performance.

[Bartacus]

Even if there is a difference, as long the temps are reasonable, it really doesn't matter much. Water cooling is mainly aesthetic, so if the loop looks good and the temps are ok, I'd go for it. 5C doesn't matter much unless you're on the raggedy edge of high temps.

[EZ's PC's]

Even if there is a difference, as long the temps are reasonable, it really doesn't matter much. Water cooling is mainly aesthetic, so if the loop looks good and the temps are ok, I'd go for it. 5C doesn't matter much unless you're on the raggedy edge of high temps.

what he said.

[Necrodead]

I did my 295x2 block and cpu block in parallel:


And the temps were the same as long as my D5 was set to at least 3. With it set to 1 or 2 the pressure wasn't enough to go through the gpu block quickly enough, but the cpu was always fine. With the serial set-up I could run the D5 at 1 with no problems.
The gpu block on the 295x2 is like having 2 cards as well due to the high restriction.