I saw a post recently that said "Make sure your cable is 24 AWG not 28
AWG, marked on the cable. Crappy cable wouldn't carry enough juice for
the drive."
The "juice" is irrelevant as the point is to transmit voltage changes
over the line, not push current to power a device. For example, CMOS
circuits have extremely little amperes flowing around and rely on
detecting voltages. You aren't trying to run a hot plate to boil water
and fry food.
If you actually provided info regarding what was this other post then we
could see the same context of the discussion that you saw.
Neither the analog or data lines from the DVD player are relying on
amperage to power the speakers. Both go to low-level circuits to the
sound chip or sound card. It is up to the sound card to amplify those
voltage changes into higher amperage signals - assuming your sound card
even has amplied outputs. Nowadays, the sound card only has low-level
outputs. The power for pushing the speaker cones is supplied by the
amplifier within the speakers themselves. Computers that have amplified
sound outputs are rare and are also old. Computers have long assumed
that powered speakers are used. It is not amperage you are pushing out
from the DVD to the sound circuits. It is voltage change.
I just installed a DVD-RW 52x. The analog sound cable that came with
it said 28 AWG. I'm not using it -- I'm just relying on the IDE
cable. But I'm curious about 24 vs 28 AWG. I thought a higher number
meant better quality?
See:
http://en.wikipedia.org/wiki/American_wire_gauge
If you ever looked at the wiring in your house, the 18-guage wires in
the extension cords you use from the wall outlet are smaller than the
12- or 14-guage wires inthe walls to those outlets. Zero-guage wire is
nearly a third of an inch in diameter. 24-guard wire is two-hundredths
of an inch in diameter. One is obviously easier to bend than the other.
The smaller the cross-section of the wire strand, the more resistance
per linear foot for that strand. A zero-guage wire has less ohmic
resistance than the same length of 24-gauge wire. But then the point in
a computer regarding data lines is to transfer a signal using voltage
(to detect a change in the signal), not to supply amperage (to power a
device). Just the opposite applies if you are trying to run a space
heater where you amperage is more important than voltage to generate the
heat.
It is because smaller diameter wires have more ohmic resistance that
higher diameter wires are used for transmission over longer distances.
However, you're talking about signal transfer over a wire less than 3
feet length and often just 12 or 18 inches. Using overly long cables
within a computer can cause problems: airflow restriction, inducted
noise, echo, cross-talk, and attentuation. So wire there is some need
to go with bigger wires, it won't make a difference in a computer if you
use the standard cable lengths. Wire size is more important for the
cables you run outside the case, like using an overly long cord between
the video card and monitor that uses small-sized wires (but then such
cheap cables also don't have the necessary shielding, anyway).
