[G4] Broadband Speed Liar's Poker

[Timothy Pitts]

On 12/13/03 4:36 PM, "Richard M. Kriss" <kriss at qsl.net> wrote:

> I know this has been discussed before but I am a new DSL user and very
> confused on how to test my download speed. When I  do the speed test thing
> at http://www.computers4sure.com/speed3.asp?Sp=1336 I get
> 
> Your Speed is: 1336 Kbps  to 1550 Kbps
> 

A site such as this is not the best indicator of speed unless the test is a
prolonged one. Some sites will test your connection for only a few seconds
then extrapolate the numbers.

> When I watch the Safari download window it says
> 
> 87.7 KB per sec
> 

Probably the server can't give you data faster due to factors such as server
load speed of the server upload, etc... Explained more below.


> Maybe I am getting confused by Kbps (bits per second) vs KB (Bytes) per
> second.
> 

I wouldn't say you're getting confused. You did realize the difference
between Kbps and KB/s.

There are 8 bits in one byte.
There are 1024 bytes in one kilobyte (KB)

If you are getting a speed of 1336 to 1550 Kbps, that means you have a speed
of 1,336,000 to 1,550,000 bps (in this instance the K stands for kilo or
multiply by 1000).

If you want to know what that translates to in KB. You take the total bps
such as 1,336,000 bps then you divide by 8 to give you how many bytes. That
will give you (1,336,000 bps / 8 bits in a byte = 167,000 bytes per second)

You now have 167,000 bytes per second. Now divide by 1024 to determine how
many KB per second you have. 167,000 bytes per second / 1024 bytes in a KB =
163 KB per second.

If you do the math with the 1550 Kbps then you have an approximate speed
(according to www.computers4sure.com) of 163 KB per sec to 189 KB per sec.


> The new DSL setup seems much faster than the old 56K dialup connection but I
> have no idea how good is good.  I have heard cable people say they are
> getting 300 KB per sec.
> 

My Cable Modem gets about 235 KB per second average. Cable Modems tend to be
faster than DSL, but bear in mind that your DSL speed should remain
relatively constant while a Cable modem user must share bandwidth with other
users on the same node.


> What is the correct term for quoting speed KB per sec or Kbps?
> 

Depends, but usually I refer to the KB per second. This is usually what you
will see in download windows. Like you said you saw in Safari.


> What is a good figure for a DSL connection?  I don't care about comparing to
> cable modems. I just want to know if my DSL is working okay.
> 

A good speed for DSL is exactly what you said you had with the 1336 to 1550
Kbps (163 to 189 KB per sec). I may be wrong, but the limit on consumer DSL
is approximately the same speed of a T1 line which is 1.536 Mbps or 1536
Kbps which is very close to your stated 1550. You have a great connection
speed if you are always getting around 1550 Kbps (180 to 188 KB per sec)


> I wonder if the speed is more influenced by the application (Safari,
> Netscape, Explorer and the new Mozilla Firebird)
> 


Regarding the other connection speed that Safari showed you and what
application might get the faster speed. Download speeds are affected by many
variables. The application is one, your connection speed is another, sharing
bandwidth (cable modem users), etc..

The single largest factor in your download speed is what does the other end
(where you're downloading from) have? The are many factors to consider when
considering the server you're downloading from.

You mentioned above that the speed you showed in Safari was 87.7 KB per sec.
That speed will change with every site you download from. Most likely, that
is the fastest that they can serve you the data.


I hope this helps..

--
Timothy Pitts
tpitts at mac.com