hm, i'm not sure how popular this decision will be, but i have seen these before, but never in any computers here.
noctua makes 80mm fans rated at 17dB, less if you use a low/ultra low noise adapter with it. CFM is unclear on the website though. 1800rpm is a lot at 12v, 1300 with a low noise adapter, less than that with the ultra low noise adapter.
the low noise adapter is actually a molex to 3 pin adapter, suited for 12, 7 and 5 volt use...7 may be your best bet.
i'd strongly suggest looking further into it before buying though, i'm not sure if its new or just not entirely popular. no harm in finding out though.
at the same time, the Mini Ninja is capable of using a 92mm fan, in which case you can use a Scythe Kama 92mm PWM fan.
that way your motherboard would be in complete control over the fan speed the same way it controls the stock fan.
the choice is yours.
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