Scaling of Cooling Performance

The Big Typhoon VX was outstanding at stock idle and above average among top coolers at stock load. However, as overclocks were raised, the VX was not particularly outstanding in the ability to cool the CPU under stress conditions. To be as fair as possible all overclocking tests were run with the Big Typhoon VX fan at the highest speed.

At 2.93GHz the retail HSF is running at 41C, compared to 27C with the VX. This is a delta of 14C. The delta becomes greater as the overclock increases. At 3.73GHz the idle with the retail fan is 56C compared to the VX at 38C - a delta of 18C. The cooling performance of the Big Typhoon VX is much better than the Intel retail cooler at idle, but the VX does not reach the same cooling levels measured with the Thermalright coolers (with a Scythe S-Flex SFF21F fan) or the stock Tuniq 120. The top Thermalright Ultra-120 eXtreme, for example, is at 33C at the same 3.73GHz, and it is still cooler than the VX at any speed measuring just 36C at the much higher overclock of 3.94GHz.

Cooling efficiency of the Thermalright Big Typhoon VX was also compared under load conditions 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 form 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 are showing similar efficiency slopes.

The VX is very efficient in cooling in the 2.93 GHz to 3.73 GHz overclock range. As you can see in the chart the slope of the line is similar to that of other top coolers in this range. The VX continues on to a highest overclock of 3.85GHz, which is well short of the 3.90GHz to 3.94GHz most of the top coolers in our testing have achieved. Compared with the top coolers, which have flat lines in this range, the slope of the VX in this range is steeper, indicating it is nearing the end of its area of efficient cooling.

The 3.85 GHz with the VX tied the Cooler Master GeminII for best performance by a down-facing fan cooler. At 3.85 GHz the cooling temperature with the Big Typhoon VX was 62C. This compares to the Thermalright Ultra-120 eXtreme at the higher 3.94 GHz at 47C, 45C at 3.90GHz, and 43C at 3.83 GHz. The Tuniq 120 is 51C at 3.90 GHz.

Clearly the Big Typhoon VX is not in the same cooling category as the best heatpipe towers we have tested. It is a decent cooler in a more limited range, but the cooling efficiency is not the equal of the best heatpipe towers.

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 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


View All Comments

  • rjm55 - Thursday, June 7, 2007 - link

    Maybe the real point is that those who bought these down-fan coolers for better cooling are just disappointed to find out they don't work as well as the top guns. Reply
  • stepone - Thursday, June 7, 2007 - link

    The point I was making was that the 120 VX (& down blowers inparticular) benefit more from exhaust fans than tower coolers do and a proper case setup will nearly always include at least 1 120mm extraction fan.

    Seriously who buys an after market HSF & then uses no case fans (HTPC users maybe but most HSF units will be 2 big for those cases)?

    As for your sour grapes implication, you're being very close minded...
    Is it not possible that other people's opinions & real world experience of the 120 VX could be different & that they're trying to simply get people to take a 2nd look at this HSF instead of being petty individuals in a vindictive jealous rage trying to steer others to the same mistake?

    As for Anand techs dissing of Hexus's tests this doesn't seem fair.

    Sure they used a different testing methodology than yours but that doesn't make their results worthless and although I disagree with some of their methodology as well it doesn't negate their results. Just as it doesn't negate yours.

    To me these 2 reviews make it clear that a case with good ventilation & 2-3 fans will benefit the 120 VX more than a tower cooler & perhaps skew you in that direction but cases with 1 or no fans should go with a tower cooler for better results.

    And yes I am happy to seed the crown of best HSF to the Ultra 120 as I do believe it is the best around at the moment. I just believe that the 120VX is a better cooler in real world cases then you give it credit for as your test setup does not reflect the type of system setup that most people will be using in their PC's.

    Still good job Anand Tech for providing a review at all.

    Thanks... (boy that was way too long :-)
  • rjm55 - Thursday, June 7, 2007 - link

    Am I dense? If the down facing fan coolers need case fans to approach cooling as well as the towers with side fans isn't this proof the towers cool better?

    It is also interesting that Wesley found the down fans and side fan models both benefited from adding a case fan. So what's the point?
  • DaveLessnau - Thursday, June 7, 2007 - link


    However if down-facing cools better, then why can't these down-facing designs compete with the best heatpipe towers in performance on our Core 2 Duo test bed?

    As I mentioned in your last heatsink review, it's because you don't have a case fan. All you're doing with the down-facing fan on this heatsink is circulating the same hot air around and around the case. All it does (all it CAN do) is get hotter. No one in their right mind would run a computer without at least one case fan, ESPECIALLY when over-clocking. In this artificial (and incorrect) test environment you've created, those side-blowing heatsink have a definite advantage since they can force some hot air out through that empty case fan slot.

    I realize you did this test in the same environment as the last one so you could compare apples to apples. But, there's no point in a proper comparison across tests when the tests themselves are faulty. Put the case fan back in your test bed and at least re-test one down-blowing and one side-blowing heatsink.
  • Wesley Fink - Thursday, June 7, 2007 - link

    Our current case does have a PS fan that removes hot air from the top of the case and rear vents to exhaust rear air, but no case fans. All coolers were tested under these consditions.

    We did test 2 of the down-facing coolers with a rear case fan installed. Cooling performance was improved a few degrees, but overclock remained about the same. We then tried the rear case fan with two of the heatpipe towers. Cooling performace was also improved using a case fan on the heatpipe towers but overclock was almost the same. We suspect that if we were testing with much lower output fans the case fan would make more of a difference.

    In the end we would need to retest all coolers with a case fan installed, not just the down-facers. Right now we doubt it would reveal more than we already know, based on quickly checking 4 coolers with a case fan.

    Our new test bed will include a "quieter" variable speed PS with a different fan configuration. We will also include a large low-rpm case fan. We do plan to retest a cross-section of the coolers for new baseline results when the new cooler test bed is finalized and updated.

  • Martimus - Thursday, June 7, 2007 - link

    I know that I have written in both of the previous reviews that blowing the hot air back onto the component is counterproductive, and that turing the fan around would help that part at least. But, the side blowing fan is just a better design. It has better airflow, and doesn't end up with the turbulence and back pressure that a downward facing fan has. Side blowing fans aren't always practical though, because they stick out much farther, and cause much more strain on the motherboard. Reply
  • strikeback03 - Thursday, June 7, 2007 - link

    The height of the VX is 150mm, including the control knob on top, so say 135mm for the top of the fan. Most of the weight is far away from the motherboard. The Tuniq Reply
  • strikeback03 - Thursday, June 7, 2007 - link

    typo submitted the comment unfinished.

    The Tuniq is 155mm tall and the Thermalrights 160.5, and I would not be surprised if they put less of a moment on the motherboard due to the mass not being all concentrated at the far end.
  • Bull Dog - Thursday, June 7, 2007 - link

    Very nice review. I love the dig at Hexus at the end. Their review really did piss me off in the fact that they used such a crappy fan on their Ultra-120. Reply
  • jkostans - Thursday, June 7, 2007 - link

    I agree, this review is 10x better than the Hexus one. The Hexus review was a slap in the face to legit reviews. Reply

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