Scaling of Cooling Performance

The Thermalright Ultra 120 was our top performer so far in CPU cooling at stock speeds. The Ultra 120 Extreme, which is the same heatsink with 2 added heatpipes, does even better. As overclocks were raised, the Ultra 120 Extreme with the Scythe S-Flex fan extended its cooling advantage over other tested coolers. The Ultra 120 Extreme outperforms the excellent Tuniq Tower 120 in cooling across the overclocking spectrum. The Ultra 120 Extreme also set a new top air-cooled overclocking record at 3.94GHz with our test X6800 processor.


The Ultra 120 and Tuniq Tower 120 set some very high performance standards for effective cooling in overclocking. By 3.73GHz, the highest stable overclock with the Intel Retail HSF, the temperature at Idle was 56C. This compared to 36C with both the Ultra 120 and the Tuniq Tower 120. The extra heatpipes of the Ultra 120 Extreme lower this to an even better 33C. By 3.90 GHz, the previous best overclock, the Idle for the Tuniq is 40C and the Ultra 120 is 37C. The Thermalright Ultra 120 Extreme drops the idle 2C lower to 35C, and is still at 36C at the highest stable overclock of 3.94GHz. This is very close to the performance level of the Monsoon II which uses active TEC cooling and not air alone.

At overclocked speeds the temperature delta increased as the processor speed was raised, so let's see what happens under stress conditions. While looping the Far Cry River demo for 30 minutes the CPU temperature is captured at 4 second intervals with the NVIDIA monitor "logging" option. The highest temperature during the stress test is then reported.


Cooling efficiency of the Ultra 120 Extreme under load conditions was the best tested so far by a wide margin. Compared to the Ultra 120, Tuniq Tower 120 and other top CPU coolers we recently tested it is clear that the extra heatpipes in the Ultra 120 Extreme are very effective in extending cooling performance.

As you can see in the chart above the cooling efficiency of the Ultra 120 Extreme under load is striking. Where the Tuniq Tower 120 and Ultra 120 mirror each other from 2.93GHz to 3.90GHz, the Thermalright Ultra 120 Extreme creates a new performance curve at a lower cooling temperature. The Tuniq and Ultra 120 are at 47/48 at 3.73GHz compared to the Intel Retail at 71C. The Ultra 120 Extreme shatters those cooling results by maintaining 43C.

The advantage increases even more as the overclock is raised. By 3.90 GHz, which is the highest overclock the Tuniq and Thermalright Ultra 120 could reach with stability, the Tuniq and Ultra 120 are both at 51C, which was the best performance among coolers tested so far. The Ultra 120 Extreme, which is the same exact cooler as the Ultra 120 with just two additional heatpipes, bests both previous leaders by 6C, with a 3.90GHz temperature of 45C. The Thermalright Ultra 120 Extreme is still able to push the processor higher, topping out at a stable 3.94GHz. At that speed, processor temperatures under stress remained a very low 47C.

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 Tuniq and Thermalright Ultra 120 is pretty average among the X6800 processors we have tested with Tuniq cooling. Other processors tested with the best air coolers ca sometimes reach just over 4 GHz, with a range of top X6800 speeds from 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 with the Intel Retail heatsink.

Cooling at Stock Speed Overclocking
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  • Ender17 - Wednesday, March 7, 2007 - link

    I'm basing my statements off of SPCR's results.
    You can read their testing methodology here:
    http://www.silentpcreview.com/article687-page1.htm...">http://www.silentpcreview.com/article687-page1.htm...
  • Wesley Fink - Wednesday, March 7, 2007 - link

    While we respect the quest for a silent PC, testing fans in a foam block isolated from power sources is not real world. It does allow isolation of the lowest possible noise that can be emitted by a component. However, in a system power supplies do generate noise, cases do vibrate with mounted fans, and the video card does have a fan.

    You can minimize all these variables in a specialized PC that is not overclocked,but many users want a system that is very competent, reasonably quiet, but still uses a power supply with a fan. That makes the PS the noise floor. The configuration (open/closed cases), measurement distance, and measurement method determines the dbA level. Our noise measuremtns aim at measuring a real world computer enviromment and they do not isolate the PS in another room for noise measurement. They should also be considered worst case noise in the cooler being tested.

    Our test room has all other equipment turned off and only incandescent lights.
  • PCTechNow - Wednesday, March 7, 2007 - link

    If you do not isolate the components for testing then why measure it all? There are so many variables within the case and your room that any measurements provided are worthless.It would be nice to see how these air coolers compare to water systems. Why is there not a review or at least a comparison in your results?
  • Wesley Fink - Wednesday, March 7, 2007 - link

    We measure and report total system noise with each cooler using a standardized test system that is typical of an enthusiast system. We have not evaluated individual fans.
  • PCTechNow - Wednesday, March 7, 2007 - link

    Is the noise level in your room and case always the same between test measurements? If you do not isolate the test parts and ensure the room noise level is equal then how are your results valid? I am not a gamer so I expect to have a quiet system. I do not think you are providing numbers that cater to the majority of people who use computers. It is hard to tell from any of your results if a unit is really quiet or not. The power supply is already at 38db so any cooler that is quieter than this will not be reported. Is there anyway to tell us if a cooler is quieter than 38db?
  • Wesley Fink - Wednesday, March 7, 2007 - link

    The noise level in my test room is always below the noise floor of the single standardized test system with the case side open. I measure the room noise each time before I begin system/cooler noise measurements.

    There is already a web site for users who are obsessed with system noise, and we are not a substitute. We are trying to address users who care about system noise and want to build a quiet PC on a relative basis - not those who make noise their only concern in choosing computer components.

    Manufacturers are definitely doing a better job of addressing noise these days - mainly because users like our reders complain about high noise components and stop buying them. There are not many 62db fans around like the screamers that used to be common on Socket A builds.

    I wish the northbrdge coolers were quieter - that is where the highest noise is these days. The Northbridge fan on the test EVGA 680i is the noisiest component in our system. It is so gbad we have to disconnect it before making any noise measurements on coolers.
  • PCTechNow - Wednesday, March 7, 2007 - link

    What is your problem with not using quieter components in the test PC or even changing rooms? Fine with not catering to quiet pc users but at least get your noise floor down to something reasonable like 30db. I am sure I am not in the minority here but most of the boards used now are passively cooled so the two main noise issues in a pc are the cooler and power supply. I am not after total silence but having something that is not louder than the ambient noise in the room is important.
  • gramboh - Thursday, March 8, 2007 - link

    The review is fine for users like me, those that are going to build a PC, want it to be REASONABLY quiet, but also overclock and have a high end video card for gaming. If you browse the AT forums, a lot of the users fall into this bucket. Yes there are also silence enthusaists, HTPC etc. If I were building one of those systems I would be reading up on SPCR.

    The review is gauging an overall end user experience.
  • kmmatney - Wednesday, March 7, 2007 - link

    "I am not after total silence but having something that is not louder than the ambient noise in the room is important."

    That doesn't really make sense - anything lower than the ambient noise will be pretty much silent. If you want a silent cpu, then go fanless. Most people have a power supply that makes noise, as well as video cards that make noise, and these reviews make sense.
  • bigpow - Wednesday, March 7, 2007 - link

    I was absent for a one year and now I never see it being compared anymore..
    How is it compared to today's top coolers?
    Is Scythe Infinity the new Ninja/p?

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