Your new webcam is USB 2.0 version which is the latest and your computer USB port version is either:
-USB 1.0
-or you connect throught a USB version 1.0 hub to your computer.
USB 2.0 runs a lot faster. You can buy new PCI USB 2.0 card and have it installed on your computer and connect your newer USB peripherals to it. Or you can leave it like that, it doesn't harm anything and it is not that slow for webcam video application.