Comparing the Antec coolers, we see that both the 620 and the 920 are very similar in concept, the 920 being thicker and featuring a USB cable on top. Both support 120mm fans and have the same length tubes. The other notable difference is the arrangements of the fins on the respective radiators. The KÜHLER H2O 620 has 12 columns of fins where the 920 only has 9 but the fin width is 8.5mm instead of 11.5 on the latter. The KÜHLER H2O 620 also has narrower fin spacing of 1.25mm whereas the spacing on the KÜHLER H2O 920 is 1.5mm on average.


The KÜHLER H2O 920 features two 9 bladed PWM fans operating between 660-2580RPM whereas the KÜHLER H2O 620 features a single 7 bladed fan operating at 1450-2000RPM.


The KÜHLER H2O 620 radiator is 27mm in thickness whereas the KÜHLER H2O 920’s radiator is 48mm thick. For comparison, a single radiator on the Noctua NH-D14 is 52mm deep.

Both CPU blocks look similar although the 620’s is 2mm shorter at 27mm. The KÜHLER H2O 620 does not feature RGB LEDs like its bigger brother instead sporting a yellow logo.