network perf : em driver ?

Patrick Proniewski patpro at
Fri Jan 12 02:32:53 PST 2007

Hi Dominic,

On 12 janv. 07, at 10:35, Dominic Marks wrote:

>> File transfert through em0 looks quite slow : at best 17 MB/s (scp
>> gives better results than http, tested with a 120MB file)
>> File copy, from one HDD to another or from one HDD to /dev/null,
>> ranges from 30 to 48 MB/s on the FreeBSD side (SATA HD).
> Try testing FTP. SCP will be doing encryption which will slow
> the process down. I can't say which HTTP would be slower than
> that.

I'm not sure encryption slows it down, the box has 4 CPU (2 dual core  
Xeon LV 1.66 GHz), and as I've said, non-encrypted HTTP was slower :/

> I have some Dell's with similar specification which will
> happily FTP back and forth at around 40MB/s which is reasonable.

I'll give FTP a try, but I would like the network to be fast for  
every protocols. I'm planning to share data using NFS, WebDAV, or SMB  
(and scp occasionally), but I've still to choose and configure  
appropriate servers.

>> I would like to know if there is a good method to find the bottleneck
>> and to get rid of it. How comes my GbE is so slow ?
> This is a dedicated network right? No other traffic?

the Mac OS X box access the Internet via the FreeBSD gateway (mac<-- 
 >em0(freebsd)fxp0<-->internet), so it's not absolutely dedicated to  
my network benchmarks. But internet related traffic was as low as  
possible during my tests (few imap sessions, one irc connexion).


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