Nein, ist kein 3,5" sondern nur 2,5". Dort ist es üblich ohne Netzteil auszukommen, sondern nur mit USB. Wusste garnicht, dass die Sachen so knapp bemessen sind.
So steht es bei WD, hier nen Auszug aus dem Support:
Why does the error "Power Surge on Hub Port" or "USB device has exceeded the power limits of its hub port" occur when you plug a USB device into a USB port on a computer or USB hub?
Answer
Problem:
Under Windows XP, an error message of "Power Surge on Hub Port" or "USB device has exceeded the power limits of it's hub port" is displayed when connecting a USB device to a USB port on a computer or Hub.
Cause:
Under some computers, USB devices are only allowed to draw a maximum of 500 milliamps (mA) per connection from the USB port on the computer system or from a USB hub. Under the Windows XP Operating System, with the release of Service Pack 2, if a device attempts to draw more than this (500 milliamps), a USB port balloon message is displayed to indicate this over current condition. When connecting a USB device that draws power from the USB bus, a very brief over current condition is sometimes detected by the OS, and the warning message is displayed.
Resolution:
This message has no affect on the functionality of the USB port. The USB hard drive should still function correctly on the USB port regardless of the error message. To prevent the USB Power Surge Alert message from displaying, please complete the following steps:
1. Click on Start.
2. Click on Control Panel.
3. Double-click on the System Icon.
4. Click on the Hardware Tab.
5. Click on the Device Manager button.
6. Click on the + next to Universal Serial Bus Controllers to expand the selection.
7. Right-click and select Properties on any listing that displays USB UNIVERSAL HOST CONTROLLER.
8. Click on the Advanced Tab.
9. Check the box that says: Don't tell me about USB errors.
If you are using a WD Passport 2.5" hard drive, please ensure that the computer's USB ports supply at least 650 milliamps through the USB ports. If your USB controller or USB hub is limited to 500 milliamps of power draw, you may need to use a USB 2.0 Power Booster Cable or a WD Passport Power Supply.