1. To the 3 pin connector or 4 pin connector on the motherboard has a limitation of power that they can provide?
2. If I will connect 2 or 3 fans together to 1 connector with adapter, will it work?
3. This question is not related to connecting a fan. How do i know how much power my pc is taking?
(q2) If all the fans are the same type and size then the adapter should work fine but fan speed won't be precise as only one of the fans tacho signals is used, (q1) theres also a limit to the amount of current the motherboard connectors can offer (check with the manufacturers specs).