Separate power supply connection

Just received the TBS6522 card I ordered, but I dare not install it.
There is a separate power supply connection on the card. Is the PCIe power supply not sufficient? Do I really have to use this separate power supply connection or is it superfluous?
The installation part of the user manual makes no mention of it.
I'm confused.
Kind regards,
Andre Hasekamp.
There is a separate power supply connection on the card. Is the PCIe power supply not sufficient? Do I really have to use this separate power supply connection or is it superfluous?
The installation part of the user manual makes no mention of it.
I'm confused.
Kind regards,
Andre Hasekamp.