Radiator position for optimal cooling

[Luck1112]

I'm going to build a custom watercooling loop for my gaming pc. The main purpose for which I'm going to watercool is silence. I don't care if temps go as high as 70 degrees, i just want peace.

My Configuration

Case: Corsair 780t
Mobo: Rampage V Extreme
Cpu: i7-5960X @4GHz @1.25volts 180W
Gpu: 2xTitan X maxwell 500W
Psu: ax1500i
Drive: Samsung 960 pro NVMe (with aluminium heatsink on the controller)

My watercooling configuration

2x 280mm rads EK Coolstream CE 280
2x Gpu EK waterblock
Cpu EK supremacy evo wb
D5 Pump radiator combo EK
Soft tubing

Case fan mounts:
2x140 top
2x140 front
2x120 bottom
1x140 rear

My doubt is wether to put the two radiators in exhaust configuration with the front one with 2 120mm fan giving air to him and the rear one with only a single 140 intaking air; OR the front radiator in intake and the top in exhaust.
The problem with the 1st hypothesis is the fans not pulling enought air inside to make the fans on the rads unable to do their job, the problem with the 2nd one is that the front intake radiator is pulling HOT air inside the case and all the other components (Ram, Pch, VRM and 960 PRO) and the other radiator will have VERY HOT air with the heat coming both from the front rad and the other components; I want to recall to mind that each radiator will be dissipating almost 350 watts, so it is not the scenario of the h100i cooling a 95W processor that doesn't heat up the air, NO. And my radiators are low restriction low fins per inch.

What would you suggest to do (DO NOT BASE ON TEST RUN WITH AIOs COOLING ONLY THE CPU, please)?

 

[massacrex]

So no matter what, you'll have a case-top exhaust, which will be pulling warm case air over the top radiator. Rather than doubling down on warm air passing over the radiator by having a front case exhaust, I'd probably go with option 2 (front intake) where you can pass "fresh" air over at least one of the radiators. One of my concerns with option 1 would be creating a negative pressure environment, where your case may start to pull dust in through unfiltered parts of your case. Option 2 would be (slightly) positive pressure, since the front intake and top exhaust pressures should offset, while the 2x120 bottom intakes should create more positive pressure than 1x140 rear exhaust creates negative pressure. Either option, I'd be surprised if the temperatures are significantly different.