Final Words

One look at the attractive Cooler Master GeminII and it is easy to understand why computer enthusiasts swoon over the possibilities of putting this cooler to work in their system. The GeminII combines an innovative design with the additional promise of cooling all the components on your motherboard. With the ability to use two 120mm fans side-by-side, blowing down from above the cantilevered heatpipe tower, your first thought is surely this is as good as cooling can get.

We were just as excited as our readers to test the GeminII. We also thought this would be cooler nirvana. There were a few cracks in the prospects in that none of the reviews so far had really compared the GeminII to a top cooler like the Thermalright Ultra 120 and the Tuniq Tower 120, but we considered that just an oversight. Perhaps more disturbing was the fact that reviews that only compared the GeminII to the stock Intel cooler did not show us results that caused much excitement. The GeminII is better than stock, but that should be the starting point with cooling upgrades - not the end point.

Now that we have thoroughly evaluated the GeminII there isn't much good to say about it, at least compared to the top coolers we have been testing recently. The GeminII is not a bad cooler; it is just not the great cooler we expected it to be. We have tested 21 cooler configurations in the last few months at AnandTech, and nine of those configurations overclock better than GeminII with the same CPU. That is before we even take in to account the fact that the GeminII uses two fans to, in many case, perform worse than a single 120mm fan.

On the cooling efficiency front, the GeminII is similarly average. Of the 21 measured temperatures, the GeminII is outperformed at idle by nine coolers; at load seven tested cooler configurations outperform the GeminII. Again we are often comparing one fan solutions that perform better than the two-fan GeminII configuration. To be fair, we have been testing the best coolers on the market for the last couple months, but there is no reason at all to expect the GeminII to fall short of the top performers. The fact that it does is disappointing.

We had planned to delve deeply into the purported benefits of a down-facing cooler also cooling motherboard components. That is now a moot point, however. Since the GeminII cannot match other top coolers in cooling efficiency or overclocking, who really cares if it cools your Northbridge better than a Thermalright Ultra 120? After all we are not using supplemental fans in our test case, and evidence that a cooler was cooling the motherboard chipset better would be extended overclocking from lower chipset/board temperatures. We feed significant voltages into the chipset in our overclocking tests, which must cycle at least 30 minutes in a gaming loop to be considered stable. Perhaps we will have better results with the Andy Samurai Master or the Thermaltake Max Orb, which are also top-fan coolers. If so, then we will do more than cursory measurements of motherboard component temperatures.

Perhaps with refinement the GeminII will join the top realm of air coolers. The GeminII concept seems to have merit, but the execution leaves much to be desired. If you look closely only about half the fins extend from the cooler CPU mounting plate to the extended fins on top - the rest merely expand the fin field for the cantilevered fan ledge. More active fins might help. The fin spacing is also too close for real airflow below the cooler. Put a hand beneath a cooler with 173+ CFM on top and you will be shocked at how little air makes its way to the motherboard. Perhaps the cantilever would be more effective at cooling if it was shorter, but then if it were much shorter you couldn't mount memory. There are certainly better minds designing coolers at Cooler Master than we have second guessing them here. We hope they will find ways to make GeminII the cooler we all hoped it would be.

We apologize if we sound overly negative about the performance of GeminII. As we already said, it is a good cooler, but not a great one. It does look great, and we all wanted it to perform as well as it looks. We sincerely hope the GeminII develops into the great performer we think it can be. The potential is certainly there, but for now the Cooler Master GeminII is a poser and not a performer. We expected more.

Noise
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  • acejj26 - Monday, April 30, 2007 - link

    Page 4...MHz, not GHz
  • AnnihilatorX - Monday, April 30, 2007 - link

    I have a feeling that the size of CPU coolers is directionaly proportional to the trend of global warming

    Don't take this too seriously

    Though the CPU TDPs are relatively constant at ~110W for high end CPUs, the coolers have been more and more elaborate.

  • Wesley Fink - Monday, April 30, 2007 - link

    While TDP (Thermal Design Power or Thermal Design Point)has not varied a great deal recently, the wattage demands of a CPU in overclocking are MUCH higher than at stock speed, and they increase as the overclocking goes up as it dramaticlly does with the current Core 2 Duo processors. The more elaborate cooler designs are to effectively cool in the highest possible overclocking configuration OR to more efficiently cool with less air volume (noise reduction).

    We evaluate coolers using both these criteria - overclocking and relative noise.

    Were we to evaluate coolers on just how well they cooled at rated CPU speed - which we do include in our reviews as "Stock Speed Performance" - our results table would likely look different and our recommendations would also be different.
  • pannivas - Monday, April 30, 2007 - link

    Maybe I haven’t searched hard enough, but until now this cooler is the only cooler that can fit my Zalman HD135 HTPC case 130mm(H) and perform good as well as silently.
  • stromgald - Monday, April 30, 2007 - link

    The Thermalright XP-120 is also a good option for low-profile cases. I saw a review where it performed better than the Thermalright MST-6775, which is in this review, so I think it should be in the ball park of the Gemini II. It's also probably cheaper since it's smaller, and quieter since it only uses one 120mm fan.
  • yacoub - Monday, April 30, 2007 - link

    So basically if you're someone who is looking for a cooler that's average amongst the top aftermarket coolers in prowess, offers a lower height that should fit in just about any case, can mount twin 120mm fans, is practically silent in operation with the right fans, and directs airflow down over the board removing the need for an additional fan to do the that, it could be seen as a good product worth using?
  • Wesley Fink - Monday, April 30, 2007 - link

    If you need a shorter cooler this could be a good choice. It can definitely be "silent" with the right fan(s). It does cool much better than the Intel retail fan.
  • thechucklesstart - Monday, April 30, 2007 - link

    If you set up the fans in a pull configuration if it would increase cooling?

    Most vehicles have a pulling fan on their radiator because it is more efficient than a pushing fan and this situation seems similar.
  • Wesley Fink - Monday, April 30, 2007 - link

    All Cooler Master diagrams and specifications show the fans mounted to blow air down toward the motherboard and components. We tested the fans mounted as Cooler Master specified. The fan wounting direction could be reversed if that is what you choose.
  • BladeVenom - Monday, April 30, 2007 - link

    I think it's would be worth testing. He's not the only one wondering if it might be better that way.

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