Radiators: the radiator with the best heat dissipation at low fan speeds (for quietest operation) seems to be the Alphacool ST30:
Fans: the fans with the best performance at the lowest noise levels seem to be the Scythe GT AP-15s:
The ST30 radiators also have the benefit of being very slim and relatively inexpensive compared to other radiators. The AP-15s have great low-speed performance and seem to be able to go down to ~700RPM with voltage control. I'm planning to get a Corsair 900D case and fit two 120.4 radiators (top and one side of the bottom chamber) and a 120.2 (the other side of the bottom chamber, next to the power supply).
However, I'm not sure if this setup will be sufficient. I estimate I will need to dissipate about 617 W of heat: Warning: Spoiler! (Click to show)
OC wattage formula: OC Wattage = TDP * ( OC MHz / Stock MHz) * ( OC Vcore / Stock Vcore )^2 4770k OC Wattage = 84 * (4.5/3.5) * (1.30/1.2)^2 = 126.75 W r9 290 OC Wattage = 300 * (1200/1000) * (1.4/1.2)^2 = 490 W Total = 616.75 W
Assuming the GT AP-15s are similar in performance (heat dissipation) per RPM compared to the Titan Kukri H PWM fans that Martin used in his radiator testing, I would expect them to dissipate approximately 110 W @10°C delta (according to the chart above) at approximately 700 RPM (the lowest RPM data point in Martin's fan testing for the AP-15s). This would imply ~37W dissipated per 120mm.
With a total radiator area of 10*120mm, this would give me only 370W dissipated @10°C delta, or ~60% of my estimated heat. In other words, I will miss the magic "10°C delta" target... but, my question is, by how much?
What will my real delta be with the above setup, and would it be reasonable? If the answer can be calculated with real math, that's great, otherwise even just a guesstimate or gut feeling would be really appreciated!
To get ~61 W dissipated per 120mm, @10°C delta, it looks like from the radiator chart I would need to run the fans at approximately 1250RPM, which on the fan chart would be ~37dB (instead of ~32dB at ~700RPM). I'm pretty sure this would not be near-silent.
I appreciate any feedback you can give! Thanks!