"Average GPU temperature in the torture test was 52.4 degrees Celsius with the stock fan configuration, and 53C with the top filter removed, a minor change within margin of error. Interestingly, temperature went up quite a bit with the 140mm intake fan added, up to 59.3C and 58.9C with the 120mm fans moved to front intake. This is where the the stock fan configuration starts to make sense.
NZXT chose negative pressure because this allows the GPU to draw air in through empty expansion slots, rather than relying on intake from the mostly-sealed front of the case. When front intake fans are added, even ones pointing towards the GPU, this airflow pattern is disrupted and the GPU can no longer pull cool air in from behind the case."