card needs Power Consumption
up to 300Wadditional 6+8 pin PCIe power required

PLEASE remember this is in ADDITION to what the rest of the gear in your system needs as well. To provide an accurate answer I would need to know everything you have in your rig. checklist: hard drives, memory, case, cpu, cpu fan, chasis fan, cd/dvd rom, periphials, etc. and the model numbers plus how many of each.

If you have it bent at a 90 degree angle it extends 1 and a quarter inches from the television set without anything plugged into the adapter. The length with a cable plugged in will depend on the length of the cables "head" or plug. With my ROKU streaming stick the entire length is approximately 5 and a quarter inches. (one picture is the swivel adapter only and the other is with the ROKU plugged in). The Adapter does not have to be at a 90 degree angle. I can only attach 2 pictures or I would show a third that mine is easily bent to very close to flat against the set without causing any bending or stress against the sets HDMI board or the back of the television. I know - why use one if it is nearly flat - I just needed about 1/16th of an inch more space to plug my ROKU stick in. This provided it.

First time in a while I have had to research a question to find an answer. Spent a little over 15 minutes researching this so please don't get mad at me for the vagueness of this answer...
"Vizio USB supports many ......" yes you see where that is going.

Best answer I can provide is to remind you that there are many format converters available for free. Nearly everyone of the major software distributors also offer free trial versions of their converter software.

Basically I am saying if you try a format and it doesn't work, then you can always convert that movie to a format you know will work.

It will work with both. I get a few milliseconds increased response and decreased lag from my 3.0 port but yes i have used it with my 2.0 port and all buttons and features work.