i need more usb ports. Im buying a powermate, and all of my ports are already taken. On ebay, some are going for as little as 5 dollers. They say that the hubs arent powered. Does this matter? im just gonna connect my dig camera, isub, and powermate to it. Do i need to spend extra money on a powered hub?
Got a tip for us?
Let us know
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
What Hub to use?
- Thread starter theipodgod16
- Start date
- Sort by reaction score
Yes. A USB device can only get 500ma at most from the bus. So a bus-powered hub can only draw that much, just like any other device. But the devices you put on that hub may each be looking for up to 500ma - short answer is, the hub may not be able to supply the power needs of all the devices.
Simple math: 4 ports x 500ma max current = potential draw of 2 amps
Edit: Just looked this up. If your hub is bus-powered, devices connected to it are limited (by the USB spec) to drawing 100ma or less. So that's another argument for getting a hub with an external power supply. Even if you don't think you'll ever have that many devices connected, if any one of them wants more than 100ma it won't work.
Simple math: 4 ports x 500ma max current = potential draw of 2 amps
Edit: Just looked this up. If your hub is bus-powered, devices connected to it are limited (by the USB spec) to drawing 100ma or less. So that's another argument for getting a hub with an external power supply. Even if you don't think you'll ever have that many devices connected, if any one of them wants more than 100ma it won't work.
I would say yes, because there have been cases of people's USB ports being burned out from constant draw from USB devices. A powered hub requires no power from the computer, and therefore would eliminate the risk of this problem.