if the card reader has a 20 pin, it'll defiantly work with a 20 pin connector. If you want to use USB 3.0 and you are connecting it into a 2.0 port in the motherboard, it's going to only go as fast as 2.0, and not 3.0. If you want 3.0, you need to put it into a 3.0 connection.
i relize that i know i can get the 3ports on front to go to 3.0 i dont rly use it much so if its in 2.0 that would be fine with me i just want to remove the pcie card from my mother board that is currently supporting it. the card is blocking my video cards fan and blocking some of the airflow in the case