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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  • Visual - Wednesday, March 7, 2007 - link

    now it's time that someone combines this 6-pipe ultra with a "TEC" or whatever its called in its base
    what could the results be....
  • Lord Evermore - Monday, March 12, 2007 - link

    Probably worse, or at least no better. The contact area of the TEC with the cooler is limited to the size of the cooler base. That's not a heck of a lot larger than the contact area of the CPU itself, and assumes you could actually fit in a TEC to cover the entire heatsink plate. A TEC generates heat, it cools one side, that heat is put out on the other side, plus extra heat from the energy used by the TEC. So you'd have more heat (and of course, the more energy used, the better the cooling, and the more excess heat generated) being transferred to the same or slightly more surface area of the heatsink. With equal contact areas, there's just no way for a TEC to actually provide better cooling. It might cool really well for a very short period, but then it would burn out if that heatsink contact wasn't able to carry away the heat well enough. If the heatsink can't cool the CPU down to ambient, it won't be able to cool a TEC any lower with the same contact.

    The old days of using TECs are pretty much gone, because of the issues involved. But when they are used, they're used in conjunction with a larger heatsink, both in contact area and radiating fin area. Or with liquid cooling.
  • Reynod - Wednesday, March 7, 2007 - link

    Nice review Wes ... liked it.

    Well done Thermalright ... good response to customer needs.

    Thermaltake should take a page out of this book and produce some decent stuff that works ... the emphasis on bling might be fine with noobs ... but they are off my shopping list as an overclocker
  • sephiros64 - Wednesday, March 7, 2007 - link

    is it confirmed that the new model will be the 120 ultra plus ? I'm sure a lot of consumers looking for this product will want this newer, better version and are concerned of the model number when ordering.
  • ceefka - Wednesday, March 7, 2007 - link

    I am still hoping for a review of this model. I want to cool my CPU fanless. The airflow is already taken care of with two Nexus 92mm intake fans @5v and 120mm Antec Tricool (low rpm) exhaust fan.

    Is that S-Flex fan also suitable to operate as case exhaust fan?
  • Wesley Fink - Wednesday, March 7, 2007 - link

    If your case can mount 120mm fans the Scythe S-Flex will operate fine as a case exhaust fan.
  • Philxxx - Wednesday, March 7, 2007 - link

    Hi,
    im fairly new to custom building computers and i wonder if there is a performance change when the heatpipes are placed vertically vs. horizontaly like your picture indicates.
    From what i understand so far a heatpipe evaporates a fluid inside the pipe and uses the vapor to transport the heat away from the CPU. Would the heatpipes and the evaporation/condensation proccess behave different when the cooler is mouted vertically like in a tower? Any chance to test this senario?

    Regards,
    Philipp
  • Wesley Fink - Wednesday, March 7, 2007 - link

    From the Test Configuration (p. 3)of the Thermalright Ultra 120 review: "All cooling tests are run with the components mounted in a standard mid-tower case. The idle and stress temperature tests are run with the case closed and standing as it would in most home setups. We do not use auxiliary fans in the test cooling case, except for the north bridge fan attached to the 680i for overclocking."
  • yyrkoon - Wednesday, March 7, 2007 - link

    I can not help but wonder how much better all the coolers in your roundup would do with a 'better' fan. There are fans out there, with two ball bearings that will push 220CFM. Granted, if memory serves, these fans also exhibit 65+ dba noise levels, but it would be interesting to see the results.

    Barring a 220CFM fan pushing too much air ( dislodging a cooler in the process, heh ), I would at least expect minimal improvements.

    http://epowerhousepc.com/delta-120x38mm-tfb1212ghe...">Link
  • Ender17 - Wednesday, March 7, 2007 - link

    Any idea when this will be available?
    Or any word of an improved mounting mechanism for 775?

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