Scaling of Cooling Performance

The Thermalright Ultra 120 Extreme has been the top performer so far in CPU cooling at stock speeds. As overclocks are raised, the Ultra 120 with the Scythe SFLEX fan maintains its cooling advantage. The Scythe Ninja Plus B is average in cooling efficiency with the stock fan. However, a swap to the specified 14 dB-A/72 CFM SilenX fan improved cooling to the levels of the top tier heatpipe towers in our reviews.

At 2.93GHz the retail HSF is running at 41C, compared to 31C with the Scythe Ninja Plus B with the stock fan.. This is a delta of 10C. The SilenX drops that temperature to 27C, or a delta of 14C. The delta with the stock fan remains about the same as the overclock increases. At 3.73GHz the idle with the retail fan is 56C compared to the Ninja stock at 47C - a delta of 9C. Performance improvements are much greater with the SilenX fan on the Ninja Plus B. At 3.73GHZ the SilenX cools to 36C, while at the highest stable overclock of 3.90GHz the Ninja/SilenX is at 42C. This almost flat line at idle at the top of our testing is an indication the SilenX is effectively cooling at idle all the way to the top speed that could be reached in benchmarking.

Cooling efficiency of the Ninja Plus B, with stock and SilenX fans, was next tested under load conditions. Results are compared to the retail HSF and other recently tested CPU coolers. The Scythe Ninja Plus B with the SilenX fan generated results almost identical to the Scythe Infinity with Push-Pull fans and reached the upper tier of overclocking performance. Results with the stock fan were average.

By 3.90 GHz - the highest overclock the Tuniq, Thermalright Ultra 120, OCZ Vindicator, and push-pull Scythe Infinity could reach with stability - the Ninja Plus B is at 62C with the SilenX fan. This is still worse cooling performance than many of other top coolers at this speed. Push-pull SilenX fans lower this only a couple of degrees more - to 60C. The Tuniq and Ultra 120 are both at 51C, which is some 9C to 12C lower than the Ninja Plus B. However, the Scythe was completely stable at 3.90GHz with the SilenX fan even though it ran a bit warmer. The single stock fan could only manage 3.83GHz so the SilenX or dual Sythe low-noise fans in push-pull configuration are much better fan setups for overclocking the Ninja Plus B.

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.

Cooling at Stock Speed Overclocking and Noise


View All Comments

  • crimson117 - Wednesday, April 11, 2007 - link


    Most of the important questions are answered on the package. Included on the typical jam-packed Scythe package are specifications, pictures and a list of compatible sockets, warranty info, and details on of the included 120mm low-noise fan.

    Also included are pictures of compatible ninjas.
  • bigpow - Wednesday, April 11, 2007 - link

    I bought the Ninja a while ago (I think AT article helped make that decision for me)
    I'm glad to know that AT cares about its readers
    Eventhough the Ninja is old (and probably doesn't make sense for new system build), a lot of us still have them and it's nice to know that the old Ninja still has what it takes.

    The suggestion to replace the S-Flex fan is also very nice.

    Thank you
  • Talcite - Wednesday, April 11, 2007 - link

    You guys mentioned that you were looking for a quiet PSU for the testing rig...

    At SPCR, everyone uses the Seasonics S12s and M12s for silence. I personally have a S12-430W and it is very quiet. I sleep less than 2 feet away from my system and can barely hear it. I haven't heard the M12 personally, but it should be near silent anyways. Maybe you guys should look into the Seasonics?
  • Gary Key - Wednesday, April 11, 2007 - link

    We will be testing several power supplies over the next couple of weeks but at this point the Seasonic based Corsair 620HX is the leading candidate for this test scenario based on the units we have on-hand. Reply
  • fic2 - Wednesday, April 11, 2007 - link

    Hopefully you will test the SilenX PS, too. If their PSs perform anything like their fans they should be good. Website:"> Reply
  • jay401 - Wednesday, April 11, 2007 - link

    Good review and definitely appreciate this recent spurt of HSF reviews. Looks like the Ultra 120 Extreme is the way to go... if indeed they've revised their mounting bracket for S775. Do you have any confirmation of that?

    Btw two quick typos: Page5 - first graph "iis", Page7 - paragraph ending with word "solution" has no period after it. =)
  • Wesley Fink - Wednesday, April 11, 2007 - link

    You have exceptional editing skills. Thanks for pointing out the typos. Corrected.

    No word yet on a modified S775 bracket for the Ultra 120 Extreme, but we will ask Thermalright again.
  • jay401 - Wednesday, April 11, 2007 - link

    Journalism degree/geek :D

    Thanks for planning to follow up with Thermalright; I doubt I'm the only potential buyer of their performance-topping design who would like to know if the product can now be installed without bending tensioning brackets. ;)
  • dm0r - Wednesday, April 11, 2007 - link

    and also ask thermalright the new cpu cooler they made....IFX-14. It really looks promising. Thanks for the review! Reply
  • Brunnis - Wednesday, April 11, 2007 - link

    So, how are we going to compare the effectiveness of these coolers when you seem to have used different fans? I can see the point of testing with stock fans (if applicable), but the thing most people want to know is which heatsink that performs the best. Your heatsink reviews also seem to be geared towards heavy overclockers, in which case testing with the stock fan makes even less sense. You don't even provide RPM figures for the fans used on the different coolers.

    I'm sorry, but I just find these reviews pretty much pointless. The testing methodology is flawed, considering the group of users that you're targeting.

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