Before we go over to the actual cooling efficiency tests let’s check how Corsair H50 performance depends on the fan rotation speed and the number of fans. To accomplish this we first installed only one Thermalright TR-FDB fan with the rotation speed changing from 800 to 2000 RPM with 100 RPM increment (±10 RPM). After that we added another identical fan installed for air exhaust from the radiator and repeated the entire test cycle one more time. The results are summed up on the following graph and table:
With a single fan the efficiency of Corsair H50 cooling system improves significantly in the rotation speed range from 800 to 1300 RPM. The lion’s share of this increase lies within 800-900-1000 RPM range, when the peak CPU temperature drops at first by 6 °C and then by another 4 °C. When the fan rotation speed increases from 1300 to 1500 RPM the temperature lowers only by additional 2 °C, while the speeding up from 1500 to 1700 RPM appears absolutely useless. By raising the fan rotation speed from 1700 to 2000 RPM we get an improvement of another 2 °C, which can’t make up for significantly increased level of noise.
With two fans installed onto the cooling system radiator for air intake and exhaust Corsair H50 immediately transforms. Its efficiency increases by 13 °C (!) at 800 RPM compared against the efficiency with only one fan and increases gradually up until 1100 RPM. When we increase the fan rotation speed from 1200 to 1500 RPM the CPU temperature under peak load drops by another 4 °C, while further rotation speed growth doesn’t affect the cooling efficiency any more, as it gets limited by small effective cooling surface of the radiator and the material used for it. The default fan of Corsair H50 works in the speed range from 720 to 1650 RPM – Corsair engineers must have studied the dependence of their system’s cooling efficiency on the fan rotation speed and had a justifiable reason not to equip their H50 with a more powerful fan. However, we don’t know why they didn’t include a second fan.
Now let’s compare the cooling efficiency of Corsair H50 against that of the best air cooler. We tested the liquid-cooling system with its default PWM fan as well as with a pair of Thermalright fans in two speed modes, and also in the same modes with the pump voltage lowered to 7 V. The CPU in this case is overclocked a little more than during the previous test session. So, here is a table with complete performance data and a summary diagram:
First of all we have to say that when the pump voltage was lowered from 12 to 7 V the efficiency of the cooling system dropped by no more than 2 °C and the already low noise level generated by the pump becomes absolutely minimal. At maximum fan rotation speed we see no dependence of the Corsair H50 cooling efficiency on the pump capacity, which primarily indicates that the radiator is the most important component of this particular cooling system. Therefore, we wish that Corsair H70 could have a 240 mm radiator preferably made of copper instead of aluminum. We didn’t test the pump MTBF at lower voltage within our today’s test session.
As for the comparison between Corsair H50 and Thermalright IFX-14, there is nothing unexpected here. The super-cooler was 4 °C ahead in quiet more and 5 °C ahead at maximum rotation speed of identical fans. Nevertheless, Corsair H50 turned out at least as efficient as the previously tested CoolIt Domino. IFX-14, which hasn’t been defeated yet, is stably 3 °C+ ahead of both competitors that is why we can admit that although Corsair H50 performed very well for an air cooler, it could have done better in liquid-cooling system terms.
In conclusion of our efficiency analysis let’s check out the maximum processor overclocking with two competing solutions participating in our today’s test session:
As you see, IFX-14 maintains the peak CPU temperature about 2-3 °C lower than Corsair H50 even at slightly higher frequency and Vcore (1.36875 V vs 1.375 V).