Fans

To get the maximum performance from the Giant Squid I recommend only the following premium quality 120mm fans. All are well-engineered, have high static pressure, are reliable, and most importantly, are very quiet.

There are a few factors that affect fan choice:

• ASIC Frequency:
  • 500 - 800Mhz - the NF-F12 5V PWM (0-1500rpm) is silent at default Bitaxe settings and very quiet even at full speed. Plugs directly into the Bitaxe for automatic speed control. The quietest fan I recommend that still has great airflow and static pressure.
  • 500 - 900Mhz - the NF-A12x25 5V PWM (0-1900rpm) is extremely quiet at stock settings and a low woosh at full speed. Plugs directly into the Bitaxe for automatic speed control. Higher static pressure for restrictive heat-exchanger styles like the 52pi Low-Profile Plus.
    
  • Above 850MHz to 900 MHz the NF-A12x25 5V PWM (0-1900rpm) should keep things cool to about 1.7TH/s, and still run from 5V on your Bitaxe. 
  • Above 900MHz - the increased heat production at these frequencies requires a very large airflow that 5V fans cannot provide. A 12V fan is required. There are several high quality 12V fans that I recommend, based on your cooling needs and how much noise you are willing to accept!
    • NF-A12x25 FLX (1350, 1700, 2000 rpm selectable)
    • beQuiet! Silent Wings 4 (2500 rpm). High flow and high static pressure for maximum cooling. Much quieter than competitive fans relative to the amount of airflow and cooling realized.
    • NF-F12 iPPC-3000 (3000 rpm) - tons of air. You'll hear it.
• Ambient Temperature - if you live in a warmer climate with no air conditioning, your Bitaxe will need more airflow (rpm), especially if you over-clock. 
• Noise - if your Bitaxe will be on your desk, or in the same room with family or co-workers you may want a quieter fan.
• Heatsink Size - a shorter heatsink will need more airflow (rpm) than a taller one at a given over-clock frequency. 
• Heatsink Surface Area - the more surface area the better it will cool
• Heatsink Mass - the more mass the more heat it will absorb and retain
• Heatsink Type - Conventional heatsinks are less restrictive and more forgiving of a fan with lower static pressure. Heat-exchanger styles such as the 52pi Low-Profile Plus are more restrictive and require higher static pressure fans to fully utilized their cooling capability.