[mikebore]

I realise that the "54 Mbps" of 802.11g is a theoretical max which will never be achieved in real life....BUT....
I timed the transfer of a 2.25 Gb (=2250 Mb) file on my network and it took 720 seconds. That calculates (I think) as 3.1 Mbps.
Then I timed the same transfer using a wired ethernet connection and it took 225 seconds which works out at 10 Mbps.

Have I dropped a factor of 10 somewhere? or is there something badly wrong with my network?

This is really bugging me so I would be really glad to be straightened out.

BTW I am using an AEBS as a wireless bridge (to a Tibook) from a router which is hard wired to two desktops.

Thanks

Mike

[f1000]

No, your calculations are wrong:

Your wireless router has a theoretical max transfer rate of 54 Mbps, where Mbps = Mega "bits" per second.

Your 2.25 Gb file equals 2250 Mega "bytes", or 18000 Mega "bits" (I'm assuming that Giga = 1000 Mb and not 1024 Mb). If you transfer 18000 Mega "bits" in 720 seconds, then:

18000 Mbits / 720 s = 25 Mbps.

Similarly, your wired ethernet connection had a transfer rate of 80 Mbps.

Remember, it's Mega "bits" per second, not Mega "bytes" per second (8 bits = 1 byte).

[mikebore]

Thanks very much for quick reply!

All is clear now.

Mike

[larkost]

Minor note: megabits should be abbreviated Mb, and megabytes should be abbreviated MB. Bytes are generally used when you are talking about a communications protocol (modem, ethernet, etc), and Bytes when you are talking about a storage system.

As f1000 touched on, you can also have the whole debate about what "mega" means (1000 or 1024).

[Scarpa]

Larkost meant communications protocols usually use bits per second, not bytes. But curiously, download managers and ftp programs generally measure in bytes per second.

The 1000 vs 1024 thing is not really an issue. Computer count in binary, 1024 is the closest you can get to 1000 using nice round binary numbers. Since those 24 units start to add up as you get in mega, giga, tera units some brilliant marketing types decided to use 1000 as the mega number so they could advertise higher capacities.

This really isn't an issue IMO, even on huge drives you're talking about a few percent discrepancy but some people are bugged by it.