What's the best way to differentiate between two fans?

[Silent but deadly]

I'm in the process of refining my first low noise oriented computer. At the moment, the two most noticeable noise sources are the CPU heatsink fan and my case fans. The heatsink is a Scythe Kotetsu with the stock fan. My case fans are Noiseblocker NB eLoop B12-2's. I have two B12-2's in the front of the case and one at the back as an exhaust.

At the lowest RPM settings for the stock Scythe fan and the B12-2's, they each exhibit undesirable noise qualities. The Scythe clicks all through the acceptable RPM range... I believe it also clicks at higher RPM's but by that point, the clicking is drowned out by the rest of the noise produced by the fan. The B12-2's produce what I can best describe as an electrical noise at low RPM's... it's similar to a fluorescent light but not as loud. In the same way that the Kotetsu fan click is barely audible, the "electrical buzz" from the B12-2's is very quiet but noticeable to an obsessive such as myself.

In a quest to see just how quiet I could get my PC, I tried some other fans I had laying around. That's where things got a little complicated. I tried replacing one of the B12-2's with a 1850rpm Scythe Gentle Typhoon. I wasn't expecting much due to the GT's higher RPM rating. I ran the B12-2 at it's lowest speed and matched said speed with the Scythe GT. To my surprise, the GT is not only quieter than the B12-2 but it can also run at much lower RPM's (roughly 300rpm, half of the B12-2's minimum), it feels like it has better airflow according to the palm of my hand and to cap it off; it's quieter too! Even at it's lowest RPM of just under 300rpm (I'll add exact numbers tomorrow), there are no annoying clicks or strange noises and the airflow, whilst weak, still feels pretty good considering the low RPM.

So where do I go from here? The GT seams better in every way but surely it's too good to be true. How can I test the difference between the two different fans? Would replacing the heatsink fan with the two case fans, first one and then the other and then running a benchmark be the best way to differentiate between the two?

[NeilBlanchard]

This is where subjective judgement is the most important thing - if you are not bothered by the noise of the Gentle Typhoon, and it has good temperatures, then go with it.

[Silent but deadly]

This is where subjective judgement is the most important thing - if you are not bothered by the noise of the Gentle Typhoon, and it has good temperatures, then go with it.

I'm going to do some more extensive testing tomorrow and report back... I'm just unsure what the best testing methodology is to differentiate between the fans.

In regards to the sound being subjective. Whilst I absolutely agree that sound quality is subjective, the sound of the GT's impressed me so much compared to the B12-2's that I'm tempted to say that it's not a subjective matter, it's a fact that they sound better... I'm not gonna say that though. I will say though that when I tested the GT's in the middle of the day, I couldn't detect any annoying noise characteristics, just a very gentle, smooth woosh of air. I wish I could afford to donate them to SPCR but I haven't got much to spare at the moment and Scythe have stopped making them.

On another topic, I've just had a look at your blog and it looks like theirs some pretty interesting stuff their. I look forward to reading some of it when I'm not quite as busy. I use Sketchup a fair bit and when I saw the picture of the gorgeous Britten bike, I knew that it was worth leaving a tab open for later.

[quest_for_silence]

So where do I go from here?

How are you controlling those fans? It's not clear, at least to me.

By the way, with a microphone, a software spectral analyzer and a sound card you might try to perform your own acoustic analysis (though it's a complex and error prone matter, so it's up to your call), if it's what you're looking for.

Said that, another classical differentiaton any SPCR reader usually make is in the relevant cooling prowess: whether you have some reliable sensors on the mobo, you may load the system at different levels, and then record the relevant temperatures.

Eventually, about those NoiseBlocker B12s and Scythe Gentle Typhoons, your preference for the latters is IMHO a somewhat expected results:

SPCR test of eLoop B12-2
SPCR test of some Scythe GTs

[Silent but deadly]

So where do I go from here?

How are you controlling those fans? It's not clear, at least to me.

By the way, with a microphone, a software spectral analyzer and a sound card you might try to perform your own acoustic analysis (though it's a complex and error prone matter, so it's up to your call), if it's what you're looking for.

Said that, another classical differentiaton any SPCR reader usually make is in the relevant cooling prowess: whether you have some reliable sensors on the mobo, you may load the system at different levels, and then record the relevant temperatures.

Eventually, about those NoiseBlocker B12s and Scythe Gentle Typhoons, your preference for the latters is IMHO a somewhat expected results:

SPCR test of eLoop B12-2
SPCR test of some Scythe GTs

I did actually say how I control the fans but that sentence must have gotten cut as I was drafting the post. I'm currently using Asus' Fan Xpert II but once I get round to benchmarking, I'll set SpeedFan up.

As much as I'd enjoy performing some acoustic analysis, I just don't have the spare cash at the moment to buy a microphone that I'll have little use for. Besides, seen as though the sound quality is ultimately subjective, if it sounds good; all I'm worried about is thermal performance.

My motherboard is an Asus P8Z77-V Deluxe. I've had it for almost three years and I've never had an issues with it. The temperatures seem to be accurate as far as a I can tell. I will be doing some benchmarking when I next have some free time but I'm just wondering whether or not the best results (for comparing the two fans) would come from installing them as heatsink fans? To my mind, that minimises the variables but I'm not particularly experienced with benchmarking so I'd appreciate any advice that can be given.

Thanks for the links to the reviews. It's interesting re-reading them as there are defiantly large parts of the reviews that ring true but to my ears, in some areas they could almost have had their descriptions switched... I think the only thing for it is for me to test again in the wee small hours when it's quieter.

[Arbutus]

I stand 2 different fans on their ends on a table with a thin plywood top (I don't have a guitar) and listen for undesirable sounds.