I have a Dell Inspiron 3668 I7, 16Gb ram, Graphics card, 2TB HDD. I have a 250 G SSD, caddy, and SATA power in hand to be installed. Power for this SSD comes from the second HDD power jack (jack #8 in the manual.
Because of reasons I won't get into here, I have 4 external HDDs in enclosures with USB 3 interfaces and I need to have anywhere from 1 to all 4 of these drives connected and on-line depending on the application.
I would like to install a 4 port USB3 PCIe card on one of the available PCIe slots. Problem is these cards require some sort of power (either a molex or SATA) cable to work properly. One worry I have is the power supply in this system is only 240 watts and I am wondering if it will be enough to drive the USB card and where will I get the power from?
Do the cards you're considering have a recommendation for the minimum PSU wattage?
You already have 2 USB3 ports on this PC. So if you need to connect 4 external USB3 drives, maybe you only need a 2-port USB3 PCIe x1 card...? That might draw less power.
And you might be able to use a SATA Y-splitter cable by connecting one arm to an internal drive and the other arm to the PCIe card.
OR, what about an external USB3 hub with it's own power brick? Connect the hub to one of the available USB3 ports and plug its power brick into the wall. Then connect 1 of your external USB3 drives to the remaining onboard USB3 port, and the other 3 drives to the powered USB3 hub. Or maybe connect all 4 to the powered hub...