There has been a debate that reducing the flow rates would result in better load temps because the water has more time to absorb the heat from the load and It also has more time in the radiators to reduce the temps
I have long argued that the above will give a appearance of lower temps but not result in lower load (CPU) temps than at higher flow rates (excluding any extra heat generated to move the water faster)

At low flow rates the water exiting the radiators will be lower than at high flow rates. but at the same time the water exiting the load will be higher, As the same effect is being applied to both the heating and the cooling parts in the loop. The result is the reduction in temps leaving the rads will be cancelled out by the increase in temps leaving the load.

In a simple world one would think the results of high and low flow rates would result in the same average water temps and therefore load temps would be the same.


In the test below you can see that the average water temps between high and low flow tests are similar but the load temps ( C Hot ) have rocketed up.

So you can see that higher flow rates result in lower load temps. (excluding any extra heat generated to move the water faster)


How i've tested
 below is a pic of my quad 226watts Qmax TEC chiller. You will also see two gpu blocks with temp probs measuring the water temps of the hot side of my tec rig . One before the chiller and one after it.

I have then reduced the flow rate a little by turning the tap close to the PSU

in the next pic you can see the resulting cpu temps and the t-balancer navigation

C Cold is the temps of the cold side of the chiller as close as i can get
C Hot is the temps of the hot side of the chiller as close as i can get

H Water is the temps of the water exiting the hot side of the Chiller block
C Water is the temps of the water exiting the cold side of the Chiller block