--- Thermal Performance, Conclusion and Certification
Thermal Performance
Clearly, there are issues using this cooler in a small case such as the Antec 900, not least those with restricted airflow caused by all the space that the GemenII takes up. That being so, we think that we need to take the GemenII back into the labs and retest it in a larger case to fully assess its capabilities for a future review.
As sold, the GemenII comes with no fans. We tested it in this passive state and also in active mode with a pair of 120mm fans. First, active performance.
Thermal Performance - Active
At idle, the active GemenII did pretty well, tying for 8th place in the thermal readings.
Under load, it dropped back a little, coming in at joint 9th but seemed to keep things well in check even though the reading was seven degrees higher than the review's best performer.
What we're unable to say for sure is whether the massive expanse of cooler was helping keep down the internal temperatures of the system, hindering things or making only a negligible difference.
Used with fans, GemenII is far from being a bad cooler – as our results show. But it's not, in our view, an appropriate solution for a compact PC case. It will be far easier to install into a bigger case and may only deliver its best performance in that situation.
Thermal Performance - Passive
Used without fans, the GemenII took second place out of the four coolers we tested this way.
As expected, the idle temperature of the CPU was higher than when cooled by the GemenII in its active configuration. The lack of fans resulted in an eight degree increase.
Under load, the difference between passive and active states was more pronounced – 15 degrees – and wasn't helped by localised airflow problems. The very shape of the GemenII means that it acts as a lid over the VRM, CPU and RAM. When used passively, heat is being trapped, rather than being conducted up to the fans and squirted away.
With the motherboard seeing a 15 degree rise under load, the cooler is really struggling in this setup, so the 36 degree rise in the CPU temperature under load is not surprising.
Conclusion
The GemenII from Cooler Master wowed the visitors to HEXUS when we first published our pictures and it did pretty well here, too. As we said earlier, though, our test rig probably hasn't given the GemenII a chance to excel - there just isn't enough space for it to do its thing.
As it stands though, we'd heartily recommend this cooler but only in an actively-cooled role and if being used in a bigger case than the Antec 900.
