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

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

[Harry Putnam]

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?

I think those numbers stand for bits, right?

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...

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.

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).

The transfer is between h4 and h5 (windows XP, windows 7) You'll note
there is 10/100 router between the whole lan and the internet.

Both of the subject machines are set to the 10/100 router as default
route.  The Gigabyte switch has no address.

                     internet
                        |
                        |
                        |
             (netgear router is lan `default route'  <= 10/100***** 
           NETGEAR ROUTER (inside address 192.168.0.20)
                  |     |     |
                  |     |     |
   (192.168.0.5) h1     |     h3 (192.168.0.7)
                        |
                        |
                   gigabyte switch
                   |            |
                   |            |
     (192.168.0.9) h4          h5 (192.168.0.17)
            
So I guess I worked another whole subject into this but really I would
like to know how to make the conversion mentioned.

But also if I should be expecting h4 h5 to be able to use GigaByte
transfer speeds.

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

[Harry Putnam]

Harry Putnam <reader@newsguy.com> writes:

> 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?
>
> I think those numbers stand for bits, right?
>
> 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...

OK, I found all that and how to figure it out here:
  http://www.wisegeek.com/what-is-mbps.htm

-------        ---------       ---=---       ---------      -------- 


But still needing some coaching about the network setup and what to
expect for data transfer in OP

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

[Adam Carter]

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>
> 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.

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

[Grant Edwards]

On 2011-02-22, Adam Carter <adamcarter3@gmail.com> wrote:

> IIRC typical speeds on 100Mbps LANs are 4 or 5 MBps. There's many
> factors that can affect speed tho.

If you're using full-duplex switches, you should easily be able to get
11-12MBps on a 100MBps LAN.

-- 
Grant Edwards               grant.b.edwards        Yow! Jesus is my POSTMASTER
                                  at               GENERAL ...
                              gmail.com            

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

[James]

Harry Putnam <reader <at> newsguy.com> writes:



> But still, when I'm trying to measure how much data is moving 

emerge bwmon,

It measures across the ethernet ports, so adjust your test,
according to what you want to measure, crossing the ethernet
port on the target system.


> and it seems quite slow for what is supposed to be a gigabyte network.

Gigabit ethernet rarely runs full out constantly, something, (ram, cpu,
interface, swith-latency....) mucks things up. Do not let your "copper"
get to long either!


>                    gigabyte switch
>                    |            |
>                    |            |
>      (192.168.0.9) h4          h5 (192.168.0.17)

> But also if I should be expecting h4 h5 to be able to use GigaByte
> transfer speeds.

Some fraction say 50% is good, if it is copper, unless the systems
are smoking "gaming" systems or of very high quality resources.

emerge iotop (then rebuild kernel)

Rebuild your kernel to use "iotop" and see what happens. You may need
to tweak your kernel parameters to optimize IO operations.....
(just gessing here)....


hth,
James

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

[Harry Putnam]

James <wireless@tampabay.rr.com> writes:

> Harry Putnam <reader <at> newsguy.com> writes:
>
>
>
>> But still, when I'm trying to measure how much data is moving 
>
> emerge bwmon,
>
> It measures across the ethernet ports, so adjust your test,
> according to what you want to measure, crossing the ethernet
> port on the target system.

First off.. thanks for the tips and help.

All I get from bwmon is a large mess of incomprehensible data ending in 

,----
| b7841000-b7881000 r-xp 00000000 03:05 6663       /lib/libncurses.so.5.7
| [...]
| b789e000-b78ba000 r-xp 00000000 03:05 7228       /lib/ld-2.12.2.so
| b78ba000-b78bb000 r-xp 00000000 00:00 0          [vdso]
| b78bb000-b78bc000 r--p 0001c000 03:05 7228       /lib/ld-2.12.2.so
| b78bc000-b78bd000 rw-p 0001d000 03:05 7228       /lib/ld-2.12.2.so
| bffae000-bffc4000 rw-p 00000000 00:00 0          [stack]
| Aborted
`----

And it has no man page whatsoever.

(it has a little help at bwmon -h)

But I recall using bwmon years ago so not sure whats happening that it
crashes for me.

>> and it seems quite slow for what is supposed to be a gigabyte network.
>
> Gigabit ethernet rarely runs full out constantly, something, (ram, cpu,
> interface, swith-latency....) mucks things up. Do not let your "copper"
> get to long either!

But that figures out to about 3-4 MB per second (assuming I did the
math right)

I said it was averaging about 230-237 MBytes per MINUTE , so giving it
a nice round 240 MB per MINUTE:

  240 / 60 = 4MB per second... and that figures out to:

  ( using this forumula: 1MBytes ps = 8000000 bits ps or 8 Mbits ps)

  4 * 8000000 = 32 Mbits ps

That is not counting packets going the other way of course, but isn't
an incoming speed of 32Mega bits per second what one might expect from
adapters capable of 100 mbps... (not gigabit (1000))


What you've shown below appears to show gigabit network between h4 and
h5.  Is that really to be expected?

>>                    gigabyte switch
>>                    |            |
>>                    |            |
>>      (192.168.0.9) h4          h5 (192.168.0.17)

If you show the top half of the diagram you snipped, you see that h4
h5 are aimed at a switch/router/firewall above, that is only 100mbps.
The gigaswitch has no address, so I'm wondering if traffic between h4
and h5 has to go up thru the 100Mbps router to communicate with each
other. 

I realized when I made the diagram that I was probably looking for
gigabit speeds where really only 100mbps was possible.

Take another look at the diagram (Knowing that h4 and h5 have there
default routes set to the netgear (100mbps) router.

Would it still be possible that h4 and h5 would communicate direct
thru the gigabit switch or would that traffic have to go up thru the
100 Mbps router above?

(Note that in the previous diagram I had mislabled (just a typo) the
gigabit switch as gigabyte switch)

                     internet
                        |
                        |
                        |
             (netgear router is lan `default route'  <= 10/100***** 
           NETGEAR ROUTER (inside address 192.168.0.20)
                  |     |     |
                  |     |     |
   (192.168.0.5) h1     |     h3 (192.168.0.7)
                        |
                        |
                 gigabit switch
                 |            |
                 |            |
   (192.168.0.9) h4          h5 (192.168.0.17)


>> But also if I should be expecting h4 h5 to be able to use GigaByte
>> transfer speeds.
>
> Some fraction say 50% is good, if it is copper, unless the systems
> are smoking "gaming" systems or of very high quality resources.

I keep having a sneaking feeling I'm making some horrible mistake in
the math, but wouldn't the speeds I posted (240 MegaBytes per min)
figure out to something like 3.2+ % of the rated 1000 Mbits.

(I really hope I haven't demonstrated idiocy levels of math)