Anartik.com’s Blog

There are a whole bunch of gimmicks and claims these days regarding computer fans. Most of it is marketing BS plain and simple. The biggest claim these days is “silent” and while there are all sorts of gimmicks, especially in the bearing department, there is not a huge differentiation between fans other than maybe colors, speeds and overall quality. Not surprising the more marketing claims the higher the price. In all reality many manufacturers merely reduced the speed of fans, in many case to useless CFM levels, and called the fan “quiet”, “silent” or even “green” hoping Joe public would bite. In just the past few months numerous new players have jumped on the market with all kinds of claims and fans moving into ridiculous price ranges.

I have been thinking about doing this comparison for a while and finally knocked it out. The first installment is for the most commonly used case fan size which is now 120mm. This comparison is not about appearances, prices etc. but about a simple method of comparing fan performance using a simple ratio of CFM / dBA (noise). The graph is straight forward and shows you how 120mm fans rank by how many CFM you get per dBA of noise. I included pretty much all the 120mm models I sell and added some other “premium” price fans I don’t sell. Simply put the higher the number the better and if you want a quiet fan at the expense of airflow the Scythe S-Flex D ($12.99) and Scythe Slipstream ($8.99) low speed are hands down the winners providing the most airflow per decibel of noise. One interesting trend you will notice, even with Scythe, is the higher the CFM goes the lower the ratio drops.

On the high flow side the Scythe Slipstream H, YS Tech, Ultra Kaze H and Delta AFB take the honors as the most noise efficient fans. They may range from tolerably loud to very loud but they offer the most flow per dBA.

The only caveat to the whole comparison is it was done using published manufacturer specs. In a nutshell there is a standard method of dBA measurement but many don’t use it, do it incorrectly, or just plain fudge the numbers. You may also ask why I did not include Silenx fans… According to what I have read across the net in real user reviews their unbelievably low noise claims are false and the fans are grossly louder than claimed and I have seen at least one major reseller is trying to dump them. Personally I would not buy them and consequently I would not sell them because I try not to sell anything I would not use myself.

Update: A new graph has been posted with more models. The Noctua NF-12-800 is now #1 although at a price of $19-25 for a 34.7CFM fan. I really don’t care for the marketing of these fans (and others) where the flow is only provided as cubic milliliters per hour (m3/h) which can only lead to confusion of the user. You can convert from m3/h to CFM by multiplying m3/h x .589. m3/h can be obtained from CFM by multiplying CFM x 1.699. Here is a good website for doing flow conversions Engineeringtoolbox.com.

A second graph has been posted that will allow you to see the bigger picture of not just ratio but CFM and dBA.

Jim Phillips
anartik.com

120mm Fan CFM/dBA Ratios

120mm Fan CFM/dBA/Ratio