Scaling of Cooling Performance

While the noise levels varied widely among the four fan configurations tested with the Cooler Master GeminII, the actual cooling performance was very similar across all fan configurations. For that reason, scaling performance will only be charted with the Noctua dual fan configuration, which exhibited the lowest noise with cooling efficiency comparable to the high-output fan configurations. The lower the line for a cooler (representing lower temperatures) the more efficient that cooler is at cooling.

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At 2.93GHz the retail HSF is running at 41C, compared to 30C with a typical GeminII dual-fan configuration. This is not the best performance seen in our tests at idle, but it is competitive with the top coolers tested so far. This is a delta of 11C. The delta becomes greater as the overclock increases. At 3.73GHz the idle with the retail fan is 56C compared to the Gemini II at 39C - a delta of 17C. The cooling performance of the Gemini II is much better than the Intel retail cooler at idle, but the Gemini II does not reach the same cooling levels seen in the Thermalright coolers or the Tuniq 120.

Cooling efficiency of the GeminII under load conditions was compared to the retail HSF and other recently tested CPU coolers. Load testing can be very revealing of a cooler's efficiency. A basically flat line, particularly from 3.73GHz upward, indicates the cooler is still in its best cooling range. A line that is increasing rapidly indicates a cooler nearing the end of its ability to cool efficiently. Lines which parallel the best coolers over a range of values indicate similar efficiency slopes.

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The GeminII is very efficient in cooling in the 2.93GHz to 3.73GHz overclock range. It continues on to a highest overclock of only 3.83GHz, which is well short of the 3.90GHz to 3.94GHz most of the top coolers in our testing have achieved. However, the sharp slope of the line from 3.73GHz to 3.83GHz indicates the GeminII is rapidly losing its ability to cool effectively at these higher overclocks. This is surprising, considerably the huge size of the GeminII combined with dual fans. Basically the Gemini II is performing no better than some of the $20 to $30 coolers we have tested.

Compare the GeminII, for example, to the lines for the Thermalright Ultra 120 Extreme and the Monsoon II Lite hybrid air/TEC cooler. Both these coolers have very flat stress performance lines as the overclock rises above 3.73GHz, which suggests they are still efficiently cooling and the CPU has run out of overclock headroom rather than the cooler reaching the limit of what it can effectively cool.

As stated many times, the overclocking abilities of the CPU will vary at the top, depending on the CPU. This particular CPU does higher FSB speeds than any X6800 we have tested, but the 3.9GHz top speed with the top tier heatpipe towers is pretty average among the X6800 processors we have tested with Tuniq cooling. A few of the other processors tested with the best air coolers reach just over 4 GHz, but the range has been 3.8 to 4.0GHz. Stock cooling generally tops out 200 to 400 MHz lower, depending on the CPU, on the processors tested in our lab. The 3.83 GHz with the Gemini II is average at best; we would expect a premium-priced CPU cooler to perform better.

Cooling at Stock Speed Overclocking
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  • Cableaddict - Thursday, June 5, 2008 - link

    This review ranks with Anantech's H2O kit review as one of the all-time low points for internet reviews.

    Once again, accurate & useful data marred by horrendous conclusions.

    To wit:

    1: Some people have small cases, like HTPC cases & such, and cannot fit any of the top heatsinks. For all of these users, the Gemini II is quite possibly the BEST heatsink that will actually fit. (It will JUST fit into a 3U rack case, with Noctua fans installed)

    2: Some people care about low noise. The Gemini II was shown, by this very review, to excel with low-noise fans. Compare any heatsink made, with the possibly exception of the Ultra-120, to the Gemini with both using 1300 rpm Noctuas- The Gemini is the clear winner.
    ----

    But sadly, the reviewer here fails to take these situations into consideration and decides to say that the excellent Gemini II is a "poser." Because this review was the first major one to be published, no one else really bothered much, and the product all but disappeared from the marketplace.

    SHAME on this reviewer. Seriously.

    FWIW, I had a DuOrb on my OC'd Q6600. I couldn't get it past 3.2 Ghz.
    I recently switched to a Gemini II with two Noctuas, and have reached 3.5 Ghz under heavy load. - And the noise is almost non-existant.

    This review blows.


  • Patrick Wolf - Monday, January 24, 2011 - link

    Exactly. Obviously this cooler isn't targeted or designed to compete against the big boys. So to say it's a poser is just plain ignorant.
  • mrseew - Thursday, December 13, 2007 - link

    was looking for a review on the gemini ii vs the 120, thanks
  • Farfle - Tuesday, October 2, 2007 - link

    I got this cooler for $1 buck after rebates from Newegg. I don't care if it doesn't cool any better than the Intel HSF; the box and metal itself are worth the $1 just to look at. They're so shiny!!!
  • Uglystick - Wednesday, September 19, 2007 - link

    I dont mind AT comparing one product agianst another in fact I welcome it as it gives me a better feel on how the product fits into the market. But I find this review a little lacking. It reviews the coolers ability to cool but states the it comes midrange in all the tests of all aircoolers tested, but i could not find any mention of how much the cooler cost in comparison to the leading performers. A little investigation of the AT site shows that the "TOP" performer costs almost double what the Gemini (the Thermalright Ultra 120 is shown as $60 and the Gemini at $33) wouldnt this indicate that the cooler is not "meant" to compete with the top line models, after all we dont compare the family sedan with a Porsche do we. There's no mention of value for $ anywhere in the article (unless i missed it) so it may not be the great cooler that you were hoping it to be but how does it compare when you bring budget and market placement into it.
  • Samus - Tuesday, September 4, 2007 - link

    you never mentioned that memory and northbridge temperatures fall off the map with the gemini II

    the purpose of the cooler isn't to be an exceptional cpu cooler. its purpose is to cool everything else, too. and it does THAT better than ANY other cooler out there. my memory and northbridge have no active cooling, so with this cooler, they run exceptionally cooler. and all at no expense to added noise.
  • jes1111 - Wednesday, May 16, 2007 - link

    Wow! Seems some people (including the reviewer) got out of bed on the wrong side.

    In common with many people, when I'm in the market for a new oiece of kit, I google up as many reviews and forum posts as I can find and make purchasing decisions accordingly. I find it significant that of all the reviews for the CoolerMaster Gemini II, yours is the only negative one. This tells me a lot about your approach.

    The fact is that the vast majority of readers/surfers/PC-owners are NOT looking to "OC this rig to 5.9GHz at 27,000 volts on air!" just so they can brag about it at playschool. And as a good and responsible review site, you shouldn't be pandering to these measurebators.

    I find your conclusion misleading and even unfair to CoolerMaster. The Gemini fits a particular need, a niche requirement if you will, and your review should reflect that instead of dismissing it as a gimmick that fails to outperform XYZ brand.

    Take my case: I have a Gigabyte DQ6 board in a Lian-Li PC-V2000 Plus II case. I've gone for a mild overclock to 3.2GHz (400x8) with the RAM running at 1:1 (800). Originally I fitted a Noctua big-tower cooler thingee. The CPU cooling was just great but I was running an uncomfortably high temp on the MCH (a common problem with tower-style coolers). Problem: on this board (and many others I'm), a tower-style cooler of the Noctua's dimensions overhangs the MCH, so I'm unable to fit a 40mm fan to the top of its heatsink to cool the wee beastie down. Solution: a Gemini II with two Noctua 120mm fans. Now I get more or less the same CPU temp as the Noctua gave me, but greatly improved MCH temp (even without the 40mm fan running) and I'm sure my RAM and power components are happier too.

    In other words, the Gemini is a VERY clever and useful piece of equipment, designed to answer a specific and not uncommon problem and it does so VERY well. So, far from being dismissed as a mere gimmick, it should be praised for bucking a fashion trend (encouraged by reviews like yours) and doing exactly what it says it will do.

    And, as others have pointed out, for HTPC applications none of the big towers will fit. Your review could/should have identified these points and given CoolerMaster the praise they deserve.

    So there! With knobs on!
  • fasdl - Saturday, May 5, 2007 - link

    Too bad it didn't do better... It has 8 maybe if you had a case with side intake it would have performed cooler? I'm actually going to build a a side intake system using the Enermax chakra case. It has a 250mm fan that would push air into the line of suction of these fans. I also notice it has 6 heat pipes like the 120 ultra extreme, it must be that they made it too short. If the fins were taller it would have had comparable surface area and done better perhaps. I really like the idea though of spreading out more instead of having it one tall tower. It blows on the ram too!
  • Blacklash - Wednesday, May 2, 2007 - link

    I noticed you have been reviewing quite a few coolers as of late. Grab a Thermaltake V1 and see how it does. I know it won't out perform the Tuniq tower and it should be good for a mid range OC. I am curious what its limits are. Below is what I am talking about-

    [url]http://www.allstarshop.com/shop/product.asp?ad=fg&...[/url]
  • yyrkoon - Wednesday, May 2, 2007 - link

    quote:

    While Zalman and a few others do make an expensive fanless power supplies


    Drop the 'an', or the 's' from supplies

    Last page, second paragraph.

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