After reading about the SP120 on the Antminer S5 thread I decided to give it a shot.
Tested fans:
Noctua NF-F12 iPPC-3000 PWM 3000rpm -
http://www.noctua.at/main.php?show=productview&products_id=80&lng=enCorsair SP120 PWM 2350rpm max -
http://www.corsair.com/it-it/air-series-sp120-pwm-high-performance-edition-high-static-pressure-fan-twin-packThe NF-F12 is about 50% more expensive than the SP120, $16 vs $24 each (prices from amazon)
All the tests were done on the same Antminer S5 using the same default 350M frequency.
The room was at a constant 65F and each run involved powering down the S5 then running it for 15 minutes before getting results.
Using 2 NF-F12s in push/pull configuration:
49C/51C | 1800rpm/1920rpm
Using 1 NF-F12 as push fan:
50C/54C | 1920rpm
Using 1 SP120 as push fan and 1 NF-F12 as pull fan:
55C/57C | 1680rpm/2280rpm
Using 2 SP120s in push/pull configuration:
59C/62C | 1800rpm/2040rpm
I will remark that the NF-F12s are about 5db louder at 1 foot distance but in the end I will stick with the NF-F12s since they provide better cooling.
The SP120s may be better when used on a heatsink but I think the high static pressure may not do as much good over the 10in of heatsink on the S5.
In the end the 110CFM of the NF-F12 won out over 63CFM of the SP120
Let me know if you have any questions.