Re: [gentoo-user] [OT] etho app rating 10/100 etc in megabytes

[Adam Carter]

>
> I've gotten confused on this problem way too many times.. I'd like to
> get some definitive starting points.
>
> When you see net adapters online they are always rated like
>
> 10/100  or 10/100/1000.  So how does one turn that notation into
> megabytes?
>

That notation is in megabits per second, or Mb/s or Mbps. Bits are shown as
lowercase b and bytes are shown as uppercase B. So you want to change Mbps
to MBps. This is stating the raw throughput, so Ethernet headers are
included.



> But still, when I'm trying to measure how much data is moving to a
> certain directory, and I want to compare it to what the adapter is
> supposed to do... (in some easy homeboy way).
>
> I vaguely remember something about 8 bits to a byte or maybe its the
> other way round...
>

Yep - 8 bits to a byte in this case. Serial comms can be a different number
of bits per byte.

>
> My homeboy transfer measurements:
>
> I measure the incoming MegaBytes as measured with `du' with a while
> loop interating in settable intervals.  So in this case when set to 60
> seconds,I now the number of megabytes that arrive in 60 seconds but
> would like to know how to convert that to the other notation.
>

du is probably not a good way of doing it, depending on how the disk system
commits the writes. Some clients show you the data rate. Maybe wget or ssh?
Cant check where i am now. Thee numbers the application states (or du) is
just the data, so doesnt take into account ethernet, IP and TCP headers.


>
> I'm seeing between 222 and 237 MB in a full minute being transferred
> and it seems quite slow for what is supposed to be a gigabyte network.
>
> This is just across two computers on my home lan, both with gigabyte
> adapters and they connect thru a gigabyte switch.  Or I hope they are.
>
> My setup looks like this in brief (simplified).
>
>
>
IIRC typical speeds on 100Mbps LANs are 4 or 5 MBps. There's many factors
that can affect speed tho.