That's very strange; the pinout for 1.0 and 2.0 are the same... the cable shouldn't make a difference... should it?
Sent from my DROID2 using DroidForums App
Actually it can, but not as a result of engineered differences (i.e. specifications), but simply due to one cable being of a higher quality in manufacture and materials than the other. Ideally, USB 2.0 architecture uses the same cables and connectors as USB 1.1 compliant products. Unforunately, only 3 out of 11 cables on the market are certified as USB 1.1 compliant (and so they may work fine in 1.1, but when pushed to the speed requirements of 2.0, they prove their inferiority. You may run into the cables that cause problems connecting high-speed peripherals. To avoid negative user experience, most vendors include USB 2.0 compliant cables with their USB 2 PCI cards and peripherals
Both 1.0/1.1 cables use a twisted pair configuration and the recommended maximum length is 5 meters (about 16+ feet). The reason for the length requirement is to stay within expected "round trip" data rate transfer times. USB 2.0 is expecting a round trip of a data packet not to exceed 1,500 Nanoseconds. Anything longer than 1,500 ns will result in a lost packet error as the computer or device simply assumes the packet is lost. (
http://en.wikipedia.org/wiki/Universal_Serial_Bus).
Since electricity travels at the speed of light (299,792 km/s in a vacuum) you might expect that the cable could be half again as long, however this is not the case.
The velocity and the electrical resistance outside a conduction is often assumed by the propagation speed of an
electromagnetic wave. In simplified systems, the speed of electricity is given as the electromagnetic wave which conveys information (
data), not the movement of electrons. Electromagnetic wave propagation is fast and depends on the
dielectric constant of the material. In a vacuum the wave travels at the
speed of light and almost that fast in air.
Propagation speed is affected by insulation, such that in an unshielded copper conductor range 0.95 to 0.97 that of the speed of light, while in a typical
coaxial cable [and also in twisted pairs] it is about 66% of the speed of light. (
http://en.wikipedia.org/wiki/Speed_of_electricity)
The USB 2.0 specification requires cable delay to be less than 5.2 ns per meter (192,000 km/s, which is close to the maximum achievable transmission speed for standard copper cable). Theoretically if you used a "low resistance" cable, you could effectively speed up that data transmission rate and therefore extend the length of the cable. Unfortunately, the higher cost of low resistance cable is a factor such that it is is not effectively affordable from a price/performance standpoint.
Also with longer cables there is greater risk of data corruption through RF (Radio Frequency) interference, similar to what you might hear over an AM radio when you drive near a power plant or factory that uses large electromechanical devices. Since USB 2.0 is about 40 times faster than 1.1, it is more susceptible to interference. To further combat this possible corruption of data, USB 3.0, which is an order of magnitude faster than 2.0 (480 Mbit/s versus 3.2 Gbit/s - 0.4 Gbyte/s or 400 MByte/s), uses an actual metallic sheath (shielding) around the twisted pairs of wires to prevent exterior interference from passing into the twisted pairs.
Still, there is the potential for crosstalk between twisted pairs which is why there is only one set of data wires in Serial communication cables such as USB 1.0/1.1/2.0/3.0, whereas older forms of data communication was done in a parallel method where there were data lines for each bit and information was sent in packets of bits with each bit sent down a separate wire in tandem with the others. This method worked fine for slower rates of communication over longer distances, but once the speeds got higher, the crosstalk became a problem and it was found that more data could be sent serially at higher speeds and over longer distances with just two wires rather than 32 or more. This is also why we have moved away from the Parallel ATA ribbon cables for hard drives and to the Serial ATA configuration now considered the standard.
So, to summarize a 1.1 cable that is well constructed will work fine for 2.0, but a crappy one will work very poorly in 2.0 yet may still work fine in 1.0. Of course a 2.0 cable should never have any problems operating in a 1.1 environment. Further, 3.0 cables (if this standard ever takes off), should work fine in 2.0 and 1.1, but neither a 1.1 nor a 2.0 cable should be used in 3.0 as they can cause data corruption and slow the transmission rates down dramatically due to error detection/correction, potentially even slower than 2.0 or 1.1.
Note: Much of this information was gleaned from several web data sources, but was then modified, re-worded and compiled by me to properly address the question and applications being discussed herein.
