[PLUG] How fast is my network, really?

[Galen Seitz]

John Jason Jordan wrote:
> On Mon, 19 Nov 2007 01:12:01 -0800
> Kris <krisa at subtend.net> dijo:
> 
>> John Jason Jordan wrote:
>>> desktop. By my calculation it ran at about 105 MB per minute. However,
>> 105MB/m / 60 = 1.75MB/s
>>
>> 1.75MB/s * 8 = 14Mb/s
>>
>> That's quite low for gig, even on commodity desktop hardware.  I backed up a
>> server the other night to my T61 over GigE, and was getting 110MB/s (6600MB/m).
>>
>> Iperf works great for performance testing.
>> http://dast.nlanr.net/projects/iperf/
> 
> Thanks to both you and Aaron for the info. Evidently something is
> seriously hanging things up. It seems to me that it must be either the
> connection (wiring or components) or the software (dar - Home User
> Backup). It should not be the hard disks, because even SATA-1 is
> supposed to be good for 150 MB/second. And both computers definitely
> have gigabit ethernet, although one could certainly question whether
> the drivers are up to snuff. One of them is my T61 laptop.

Just because the interface to the drive is 150 MB/s doesn't mean your 
drive can fill it.  For example, a recent model Seagate Momentus 
5400.4 drive has a SATA-3 interface, but it's sustained rate is 806 
Mb/s, or roughly 200 MB/s.  You may want to run the disk/filesystem 
performance tool 'bonnie' to get an idea of your disks' throughput.

galen