Overclocking

As cooling solutions do a better job of keeping the CPU at a lower temperature, it is reasonable to expect the overclocking capabilities of the CPU will increase. In each test of a cooler we measure the highest stable overclock of a standard X6800 processor under the following conditions:

CPU Multiplier: 14x (Stock 11x)
CPU voltage: 1.5875V
FSB Voltage: 1.30V
Memory Voltage: 1.90V
nForce SPP Voltage: 1.35V
nForce MCP Voltage: 1.7V
HT nForce SPP <-> MCP: Auto

Memory is set to Auto timings on the 680i and memory speed is linked to the FSB for the overclocking tests. This removes memory as any kind of impediment to the maximum stable overclock. Linked settings on the 680i are a 1066FSB to a memory speed of DDR2-800. As FSB is raised the linked memory speed increases in proportion. The same processor is used in all cooling tests to ensure comparable results.

Highest Stable Overclock (MHz)

The Cooler Master GeminII with the best of the dual fan configurations reached 3.85GHz in the overclocking test. This was below the top coolers evaluated so far, which generally reached 3.90GHz to 3.94GHz with the same CPU and configuration. The design of the Gemini II seemed voltage limited to 1.5635V on this 680i motherboard, since any attempt to go higher in voltage for a higher overclock would crash. This compares to 1.6V capability with the top air coolers in our tests. Consider that the 3.85GHz result was with a high output fan with noise at more than 50 dB-A - nearly 60 dB-A, which is as loud as our tests have reached so far. The other three fan configurations all topped out at an overclock of 3.83GHz, which is even worse.

The overclocking results are even more disappointing when you compare cooling results under stress to the best air coolers we have tested. Considering the amount of board real estate required by the GeminII, the heavy weight of the cooler, and the dual fans putting out massive amounts of airflow, the overclocking results are extremely disappointing. The best air cooler tested topped out at 3.94GHz. The rest of the best air coolers reached 3.90GHz. 3.83GHz is average performance, and no challenge for the best tested so far.

Scaling of Cooling Performance Noise
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  • yyrkoon - Wednesday, May 2, 2007 - link

    err, make that the second to the last page. Sorry.
  • dm - Monday, April 30, 2007 - link

    Nice review Wesley. I have owned this cooler and it does have its own merit. While it failed to beat the competition, what I can share is that I used this fan on an overclocked QX6700@3.2GHz at stock vCore and it performed great. If anyone would like to use it to achieve 3.8GHz+++, I suggest they get a quad core instead, say an X3210 and overclock it to 3GHz and use this cooler with a silent fan. With such cooling power, and since I have tested it personally, this cooler is great and should perform at par with competing ones.

    My only gripe is the price. The Ninja RevB I owned can cool the same quad core at same voltage but with much lower price tag.
  • joex444 - Monday, April 30, 2007 - link

    This thing just got pwned. It's obviously a poser. All the extra fin space did nothing, and a 2nd fan proved to be a novelty.
  • LaGUNaMAN - Wednesday, May 2, 2007 - link

    Thanks for the review. I was waiting for this a long time. Definitely the best Gemini II review out there. (^^,)
  • evident - Monday, April 30, 2007 - link

    is it me or does thermalright xp/ultra/whatever 120 series own the competition constantly? every review i read this cooler dominates the market. I'm happy to own an xp-120 and that it's not getting topped anytime soon it seems :)
  • stromgald - Monday, April 30, 2007 - link

    Um, the XP-120 has been topped by the Ultra-120 (which is a completely different design than the XP), Scythe Ninja, and Zalman CNPS9500 to name a few. The Ninja barely edges it out, and the Ultra-120 beats the XP-120 by a good margin. The Zalman beats it in °C rise per W of processor heat, but is also noisier. Thermalright's good, but it's not like the competition is that far off at all.

    P.S. Thermalright doesn't have a 120 'series'. It's more like the XP series (XP-120, XP-90), SI series (SI-128, SI-97), and Ultra Series (Ultra-120, Ultra-90). The number is related to fan size, the name is the overall design/series.
  • Wesley Fink - Monday, April 30, 2007 - link

    Thermalright has advised that the Ultra-120 eXtreme issues with the Socket 775 adapter have been resolved and the eXtrme is now in full production. For those who asked, the IFX-14 production has been delayed and Thermalright is now looking at an end of May release for the IFX-14.

    We will do an update on the performance of the production Ultra-120 eXtreme which is on its way to the labs.
  • TA152H - Monday, April 30, 2007 - link

    Not to state the obvious, but shouldn't you have tested this thing with no fans? I mean, you get a heatsink with no fans at all, that says it can run with no fans, and kind of sucks when used with fans. Hmmmm, would kind of hit me like an airborne brick that I should probably test it without any fans at all, and see if it works. Cooler Master in my experience has been a pretty good company, and it makes me wonder why they made a cooler like this one that sucks so bad. Except maybe it doesn't, and for whatever peculiar reason is exceptional at running with no fans vis-a-vis other heat sinks with no fans. Of course, it could suck at that as well, but it's so obvious a question, I'm surprised no attempt was made to answer it. It could also be potentially useful. A sucky cooler like this is of little or no interest to people with fans, but if it cooled as well as a stock heat sink/fan, without the fan, that would be attractive to a much greater audience.

    I'm also surprised they are still making these massive beasts. With the death of the horrible P7, you'd think they would start making more reasonable sized heat sinks - unless they needed it this big to work fanless.
  • Wesley Fink - Monday, April 30, 2007 - link

    We did try to test with no fans, but temperatures immediately ran to 70C under load at stock X6800 speeds and the system rebooted. I was not comfortable continuing a "no-fan" test under those conditions. perhaps this should have been mentioned in the review, but the results already pointed to less than stellar cooling efficiency compared to the Thermalrights, for example, which actually did fanless cooling within acceptable temperature ranges.

    As we have also stated several times, our current test bed is not well setup for testing fanless coolers. THe new test bed, which will be introduced with the 120mm fan roundup, is much better in that regard and will better support reliable, comparable results with fanless cooling.
  • TA152H - Monday, April 30, 2007 - link

    OK, thanks.

    I think you should mention that in the article, because that was the first thing that popped into my head. "Can I use this thing fanless at stock clock speeds?"

    With regards to the poor cooling, with some stuff it's bad to extrapolate data, even if it's logical. More specifically, it could be possible that one did better with fans, and another without, so I resist making assumptions on stuff like that. Put another way, if you were a designer, and I told you to make two heat sinks, one that was designed to work with a fan, and one that was designed to work without, would they end up being different? I would think so, but really I don't know enough to be sure. Consequently, I think stuff like that should be spelled out instead of assumed. In this case, it sucked at everything, but that may not always be the case.

    Anyway, thanks for your response. I wouldn't want to ruin my processor either, so I can understand why you'd stop testing right away. I would have done the same.

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