Water cooling loop order

Oct 7, 2018
I see a lot of builds with the water cooling loop going from reservoir > pump > GPU > CPU > radiator > restart. Doesn't this just carry the hot water from the GPU to the CPU? Is a setup where you add another radiator between the GPU and CPU better ( reservoir > pump > GPU > radiator 1 > CPU > radiator 2 > restart)? Has anyone benchmarked the difference?


Doesn't make a difference. There's 2 things goin on in a loop regarding the liquid. Liquids take a huge amount of energy to heat even 1°C. When that liquid passes through the gpu block, it's absorbing a ton of energy, but that doesn't mean the liquid is instantly heating up, it's actually a very slow process. Picture a pan of water on the stove, even at high settings it takes forever to get warm.

So that liquid is absorbing the heat energy, goes onto the cpu block and absorbs more energy, goes to the radiator which absorbs that energy out of the liquid and then dissipates it. Under long periods of use, the liquid will finally start warming up some, picture that same pan on the stove, the cpu is trying to hit 70+°C, that stove on high is over 350°C, so figure how long it would take to boil water when the stove is set on low, all day, if it ever did.

Full liquid loops are all about the transfer of heat energy, not the heating and cooling of the liquid, which honestly doesn't change much at all. So placement of rads or blocks doesn't really matter, the loop itself is a whole unit whose design is intended to remove the energy from the liquid, which prevents/slows the liquid from changing temps.

It's why loops are calculated in wattage, how much wattage is put into the loop will determine how much radiator space is needed to dissipate that wattage.