Maximum number of case fan per sys fan header?

xmasterjay

Commendable
Feb 8, 2017
2
0
1,510
My motherboard only has one 3 pin sys fan header and i just bought 5 case fan for the casing . i was wondering whether or not i can connect all 5 fans in one sys fan header with a splitter/ fan hub ? I've done all the math and all the 5 fans will use a total of 0.44A . Can my motherboard handle the number of fans and high current ?
 
Solution
It is not the actual number of fans that determine the maximum quantity you can install off of 1 fan header. It is the total current draw of the fans themselves. Typically, fan headers in motherboard are rated at 1A maximum (unless otherwise specified in the manual like the Asus MB's W_PUMP+ header and H_AMP header which can provide up to 3A).

If you fans rated at 0.3A (which is typical in case fans), then, technically, installing 3 of these fans will draw 0.9A of that 1A header. This is quite pushing it to its limit, so, for headroom, it is recommended to just install 2 of these 0.3A fans for a total of 0.6A power draw.

But if your fans are rated much less, like in your example a 0.088A fan, then, technically, you can install up...

raisonjohn

Expert
Ambassador
It is not the actual number of fans that determine the maximum quantity you can install off of 1 fan header. It is the total current draw of the fans themselves. Typically, fan headers in motherboard are rated at 1A maximum (unless otherwise specified in the manual like the Asus MB's W_PUMP+ header and H_AMP header which can provide up to 3A).

If you fans rated at 0.3A (which is typical in case fans), then, technically, installing 3 of these fans will draw 0.9A of that 1A header. This is quite pushing it to its limit, so, for headroom, it is recommended to just install 2 of these 0.3A fans for a total of 0.6A power draw.

But if your fans are rated much less, like in your example a 0.088A fan, then, technically, you can install up to 10 of these 0.088A fans as 10 x 0.088A = 0.88A (pushing it to its limits). So, if you have done your math correctly and have checked the actual power draw of your fans, then, installing those 5 fans you purchased will only draw 5 x 0.088A = 0.44A (as you have computed) from that 1A header (leaving you with 0.56A headroom).
 
Solution