Hi,

Whenever I connect my USB 2.0 External Hard Drive to my computer, I get a message saying 'Non High Speed USB device plugged into High Speed USB Port". Why is this happening?? How can I get true USB 2.0 speeds??

Thanks,

sweetboy

 

I guess it depends on what make and model extnl. drive it is..

 

Your drive is most likely only a 1.1 drive. Like AxlMyk said, need to know the make and model.

 

Could it be the cable is not usb 2.0?

 

There is no such thing as a non-USB 2.0 cable. Better cables are better shielded and will handle faster speeds better (more reliably), but nothing in the cable tells the PC anything.

The problem is that you have a something in the mix that is NOT USB 2.0. Either it is the hub used (if you are using a hub), or the the drive or it's enclosure.

 

http://en.wikipedia.org/wiki/USB
USB supports three data rates:

A Low Speed rate of up to 1.5 Mbit/s (187.5 kB/s) that is mostly used for Human Interface Devices (HID) such as keyboards, mice, and joysticks.
A Full Speed rate of up to 12 Mbit/s (1.5 MB/s). Full Speed was the fastest rate before the USB 2.0 specification and many devices fall back to Full Speed. Full Speed devices divide the USB bandwidth between them in a first-come first-served basis and it is not uncommon to run out of bandwidth with several isochronous devices. All USB Hubs support Full Speed.
A Hi-Speed rate of up to 480 Mbit/s (60 MB/s).
Though Hi-Speed devices are commonly referred to as "USB 2.0" and advertised as "up to 480 Mbit/s", not all USB 2.0 devices are Hi-Speed. Hi-speed devices typically only operate at half of the full theoretical (60 MB/s) data throughput rate. The maximum rate currently (2006) attained with real devices is about half, 30 MB/s.[3] Most hi-speed USB devices typically operate at much slower speeds, often about 3 MB/s overall, sometimes up to 10-20 MB/s. The USB-IF certifies devices and provides licenses to use special marketing logos for either "Basic-Speed" (low and full) or Hi-Speed after passing a compliancy test and paying a licensing fee. All devices are tested according to the latest spec, so recently-compliant Low Speed devices are also 2.0.

http://www.everythingusb.com/forums/showthread.php?threadid=798
jlucas
Newbie

Registered: Jun 2003
Location:
Posts: 4

OS: 98, ME, 2000, XP

USB 1.1 vs. 2.0 cables

So then are USB 1.1 cables the same as a 2.0 cable?
billyd
Forum Moderator
USB Tech Specialist

Registered: Jan 2002
Location:
Posts: 10160

OS: All Windows


No they aren't. Using the wrong cable is the most common reason for USB 2.0 issues.

 

I have an Iomega 80 Gb USB 2.0 HDD. I don't see a model number on it.

Thanks,

sweetboy

 

all the usb cables should be shielded and twisted pair type (able to transmit up to USB 2.0 speeds (480 Mb/s). The "not" kind is used for mice, keyboards, etc. that only needs the Low Speed USB.
the cable that comes with that drive is listed as usb 2.0