R10- Fan Testing-Bitfenix,Noctua,Silenx,NoiseBlocker,Phobya

Posted: May 7, 2012 in Fans, Uncategorized
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In the continued pursuit of the ultimate radiator fan, I bring you round #10.  This round was brought to you buy “cpachris” from overclock.net.  He sponsored 5 never tested before fans including the new Bitfenix Spectra Pro Black, Noctua NF-F12 PWM, Silenx Effizio, Noise Blocker M12-S2, and Phobya Naon-G12.  I put these up to the test against the previous undefeated Gentle Typhoon AP-15.  While many fans are good in case fan applications, few seem to rival the low noise output of the GTs once mounted to a radiator.  Unfortunately the GTs are not perfect either, they are a rather boring grey/black color scheme, they do have some resonance issues at specific RPMs, and they are often out of stock and suspect to overpricing due to their high demand and inadequate production.

With that, let’s bring it!


For the test rig, I’ve built an exhaust collection chamber that’s basically a long piece of 8″ PVC with insulation, a bunch of flow spreader tubes, and an MCR120 radiator mounted to the face of it.  The anemometer hot wire sensor is then mounted to the back of this to measure air speed through a smaller port.  The chamber’s purpose is to collect the fan exhaust, straighten it out, and provide a consistent means to measure it in a fixed spot without creating additional noise.

I am using an Extech Hotwire anemometer that is set to zero at the start of the round left alone the duration of the test.  For control and check, I test the first fan again after all other testing to be sure the hotwire didn’t go out of calibration.  I have found in the past that it can happen, so this extra test is to ensure data is good relative to the fans tested in this round only.  It’s a good meter, but I still don’t trust it without doing the checks.  It is however a hotwire meter which more importantly doesn’t have a vane probe to warm up or create noise.  The only drawback is dust and temperature changes can cause calibration issues. For noise level I am using a basic noise meter measure A-weighted dbA.  The radiator is a Swiftech MCR120 as shown below:

The video is via Canon T2i and audio via Zoom H1.  Not shown in the photo, but I place the Zoom on a tripod in line with the fan at a 12″ distance and the zoom has a foam wind protection sock on it.  The lens used this round was the kit 18-55 as opposed to the Tokina shown below, but you get the idea good HD video and good HD stereo audio are at the heart of the tools.

I combine the video and audio in Sony Vegas 9, add the text notes, and export to an 8MB/sec wmv before uploading to youtube.  During this combining effort, I set the T2i audio to mute and turn on the Zoom H1 audio. I use a double finger snap to create a wavform mark so I can line the two up.  Then I trim the whole thing to start/end of the test done.

Alright, enough of the testing setup, let’s get to the results


Here is a summary of what the video meters produced.  Sorry about the lack of RPM data on the Silenx, but something was odd with the Hz readings, so I pulled the data off.  The Gentle Typhoon AP-15 results are still the strongest of the bunch in terms of CFM per dBA, however I would as usual encourage you to evaluate the noise characteristics in addition to noise level for a more complete picture.  I have received messages by some readers indicating that they can’t stand the noise type of the GTs and I would agree that they do produce a different type of noise that may or may not be what you are willing to put up with.  The GT’s also do have a habit of resonating as specific RPMs as can be seen by the bump in the noise chart below. The GTs just have a special fan blade that seems to bury nearly all air type noises into the radiator which is good, but it also tends to have a little bit of bearing whine and the motor noise is present perhaps a bit more than other fans.  I think the noise quality of some of the other fans is superior, but the GT-15 remains dominant in noise level.

The noiseblocker actually has good noise ber RPM, but isn’t pushing as much air per RPM.  The Noctua has a very good CFM/RPM similar to the GT15 leaving some of the others as much as 200RPM behind. Regarding looks, I liked the noiseblocker, Phobya, and Bitfenix better than either the Noctua or GT.  As far as build quality goes, the GT probably gets my vote as it has a larger hub with metal bearing casing and dual ball bearing construction. The Noctua probably provides the most accessories giving you several resistor options to reduce fan speeds if you didn’t have a fan controller. Finally, there is PWM control which is only provided by the Noctua in this bunch.  You could however control the others via software tools like a Sunbeam Rheosmart without much extra cost. So there you have it, another round of 120mm fans and the GT-15 is still king of noise level, however there are other factors to consider that may sway you toward other options.

A special thanks goes out to “cpachris” from OCN for sponsoring these fans and my many supporters for sponsoring the tools, equipment, and website.



  1. Howard says:

    Hey Martin, i truly enjoy reading your site. it’s really insightful. i was wondering if you don’t mind testing out a new fan. looks like swiftech came out with a new fan looks to be based on the Gentle Typhoone desgn, called Swiftech Hellix 120mm PWM. it looks to be the same design but branded under swiftech. they even put out a manufacture chart comparing to the Gentle Typhoone at 1850rpm. the reason i am interested in this fan is because it’s 4pin PWM, that means i can connect it to the 8 pin splitter hub by swiftech and have it hooked up to the CPU fan header and have all the radiator fans controlled by the PWM. as currently i cannot find an equivalent splitter that’ll allow me to connect up to 7 fans that are 3pin, and STILL be able to control the RPM through a single CPU fan header. i really wanted to get the gentle Typhoone 15 after reading you in depth review, however, it’s just not possible in my current setup. this new Swiftech Helix 120 pwm seems to be based on the same design but will allow me to achieve what i want to do with PWM. would you mind testing it out to see if it indeed is like the Gentle Typhoone?

    • Martinm210 says:

      It’s a good fan at a great price, and actually has similar noise vs RPM in a kit. The gentle typhoon is superior though when you start measuring thermal performance or noise vs air flow. The PQ curve on the GT has a very pronounced bump which gives it a significant pressure advantage at similar RPMs. The helix is very flat. I still like the helix for it’s low cost, good looks, and good performance. But no it is not a GT replacement in noise vs air flow on a radiator. Short of Delta AFB1212 VHE at high speeds, no fan has really even come close to matching the low noise per air flow as the GT in the 1500-1800 rpm range. They have and continue to be the king although I am hearing they may be going away per some rumors. I hope there is a few more equivalents or improvements in the works somewhere.