does it matter if a power supply has one big 120mm fan or two 80 mm fans?
- Angry CLv 71 decade agoFavorite Answer
This is one of those hard to answer questions because you're actually asking about efficiency. Theoretically, two 80mm fans should move more air than one 120mm fan because of greater surface area and being placed further apart with overlapping coverage ( picture a sideways 8 ). But how many blades does the 120mm fan have and at what speed it it rotating? More blades and faster speed could be more efficient than fewer blades, slower speed. From a practical standpoint, I'd go with the two fans especially if they can run independently of one another. If one fan fails you'll still have some air circulation vs. no air circulation if a single 120mm fan fails.