Upgrading H100iGTX

I got my H100iGTX when it first came out, off the top of my head, I am reaching the 70k life span of the pump. So I bought the following Corsair products: 2 x 240 slim radiators, XG7 GPU & XC7 CPU water blocks, XD5 pump and all fittings and soft tubing. The loop I had in mind was pump to rad1, to GPU, to rad2, to CPU and back to pump. I have read others say that a front and top radiator is bad because the hot air from the front rad will heat up the top rad. But in Corsair configurator, there is a front and top rad design. Anyone try this? Does the hot air from the front rad affect the top rad cooling efficiency?

Most people working in a standard shape case are faced with this obstacle. Generally, loop order does not matter. This is one example where it is helpful to route it in a specific way. The effectiveness of the radiator is tied to the temperature of the air entering from the intake side. In order to get the most out of it, you really want to go:

 

CPU or GPU -> top radiator (exhaust) -> front radiator (intake)

 

There is a relationship between the radiator exhaust temperature and coolant temperature. This way the highest exhaust temp is vented out the top, the coolant drops 1-2C, then enters the front. This helps to ensure the air entering the top radiator is just slightly colder than the coolant already in the radiator. What happens if you don't? In an extreme situation you might heat the coolant up 1-2C as it goes through the top. More likely is the top radiator is just wasted and you get minimal to zero coolant temp drop through the pass.

 

It does not matter where the pump/reservoir fits into the loop. It does not matter to the overall coolant temp if CPU or GPU goes first. It does matter specifically to the CPU/GPU which is first. Your CPU likely runs 2C warmer if after the GPU heat pick up and the GPU likely runs 1-2C warmer if after the CPU heat pick up (TDP and CPU dependent).

 

The alternative arrangement to the above is to run either both radiators as exhaust (reverse flow) or both as intake. My problem with the dual intake is most cases won't be able to remove the heat dumped in and effectively you heat the case to the coolant temp, nullifying a lot of the cooling potential. Reverse flow dual exhaust works better, but a lot of people won't want to run that way because of aesthetics or just because it is unfamiliar.

Edited June 3, 2020 by c-attack

Thank you for the advice, I will definitely look at what you've written. Since I'm still waiting for a few parts I still have time to think on the upgrade.