Modem connection speed is almost completely independent of the OS. It is
the two modems (yours and the ISP's) that negotiate the speed at which they
will make a link. Think of the communication path between you sitting at
the keyboard and the final destination as a series of little boxes each
connected by a wire. Each box has to talk with only its immediate
neighbours and negotiate the speed at which it will send and receive data.
At your end there is the keyboard that talks via its cable to the computer
that talks via the serial port to the modem which talks via the phone line
to ISP's modem which talks to other little boxes at the ISP's computer room
and finally to someone else via many little boxes on the internet.
So, if your modem connection to the ISP modem appears as 14k or 28k or 50k,
it is the end result of the negotiation between your ISP's modem and yours.
The noise that you hear when connecting, is the two modems negotiating a
common (and fastest) speed at which they intend to make their link. That
speed is dependent on the design capabilities, eg, 2.4k, 14.4k, 28k, 56k of
the slower modem. (A "56k modem" will actually connect at a max of 50.6k)
They must agree to the same speed else they hangup. It is also a speed at
which the error rate is acceptable to both modems - the final negotiated
speed is thus also phoneline quality dependent. Phone line quality is not a
constant and may be affected by the weather especially if the exchange is
far away. If you consistently get better than 40k connections on a 56k
modem, be happy!
Be aware too that the apparent speed at which you send is always and
measurably slower than the speed at which you receive data. That's by
design - it's a compromise for bidirectional data exchange when using
ordinary phone lines. You'll notice that it takes longer to send large
email attachments than to receive them.
If you plan on doing a big download, check the connection speed. If less
than say 45k, consider whether it's worth your while hanging up and
dialling again later to see if you get a better connection. As someone else
has advised, the ISP's fast modems may all be busy when you try first time
so consider waiting for a less popular time of day..
You can control the speed at which your computer talks to your modem and
this, generally speaking these days, is automatically set up for you when
the OS installs the modem. The most common serial port speed setting
nowadays is over 100k so that it is much more than the maximum modem
speed. That way, the serial port speed does not limit 56k modems - weakest
link and all that.
Hope this helps and puts your mind at ease.
Richard M.