Question / Help USB3.0 Bandwidth Limitations?

[Jaxel]

I know USB2.0 has severe bandwidth limitations. Its why you can only have 1 or 2 webcams plugged in at a time; anymore and the USB2.0 bus cant handle it. However, I am using a USB3.0 discrete card to handle inputs from two AVerMedia Extremecap U3.

http://www.newegg.com/Product/Product.aspx?Item=N82E16815114010

This is a 4 port USB3.0 card with a Renesas chip supporting 5gbps. Connecting two Extremecaps to this card, I noticed that neither of them work. However, the moment I unplug one of them, the other card suddenly starts working, and vice versa. Is this normal? Or do I have a bad card?

 

[paibox]

The 5Gbps is not per port, but rather for all the ports combined. The cards SHOULD work, just not at full 1080p60 resolution.

 

[Jaxel]

Shouldn't 5gbps be more than enough for 2 cards?

 

[paibox]

Sure, but it's still just a PCI Express 2.0 1x card, which has a maximum transfer rate of 500 megabytes per second, or ~3.9 Gbps. You will most likely be able to do 2x 720p60 or 1080p30, but not 2x 1080p60.