Re: Debian server for backups of Windows clients

[David Christensen <dpchrist@holgerdanske.com>]

On 09/09/2016 11:51 AM, Celejar wrote:
> On Tue, 9 Aug 2016 18:57:02 -0700
> David Christensen <dpchrist@holgerdanske.com> wrote:
> 
> ...
> 
>> My laptop has 802.11 a/b/g WiFi and Fast Ethernet.  Wireless data
>> transfers are slow (~50 Mbps).  Wired is twice as fast (100 Mbps); still
>> slow.  Newer WiFi (n, ac) should be faster, but only the newest WiFi
>> hardware can match or beat Gigabit.
> 
> You get ~50Mbps over a/b/g? 54Mbps is the theoretical maximum, and
> everything I've read says that 20-24Mbps is the real-world maximum.
> 
> Celejar
> 

Benchmarking using WiFi (48 Mb/s):

    2016-09-09 20:18:51 dpchrist@t7400 ~
    $ time dd if=/dev/urandom of=urandom.100M bs=1M count=100
    100+0 records in
    100+0 records out
    104857600 bytes (105 MB) copied, 12.6709 s, 8.3 MB/s

    real	0m12.703s
    user	0m0.000s
    sys	0m12.481s

    2016-09-09 20:19:32 dpchrist@t7400 ~
    $ time scp -p urandom.100M samba:.
    urandom.100M


                          100%  100MB   1.5MB/s   01:08

    real	1m16.023s
    user	0m4.548s
    sys	0m0.744s


So, 1048576900 bytes * 8 bits / byte / 76.024 seconds

= 110341671 bits/second


Testing again using Fast Ethernet (100 Mb/s):

    2016-09-09 20:29:54 dpchrist@t7400 ~
    $ time scp -p urandom.100M samba:.
    urandom.100M


                          100%  100MB   2.4MB/s   00:42

    real	0m43.377s
    user	0m4.476s
    sys	0m0.876s


So, 1048576900 bytes * 8 bits / byte / 43.377 seconds

= 193388552. bits/second


Wow.  Even worse than I was expecting...


David