Re: Why is my gigabit ethernet so slow?

[Thor Lancelot Simon <tls%panix.com@localhost>]

On Tue, Jan 26, 2010 at 04:49:34PM +0200, Antti Kantee wrote:
> On Tue, Jan 26, 2010 at 01:53:13PM +0000, Matthias Scheler wrote:
> > On Tue, Jan 26, 2010 at 02:46:26PM +0200, Martti Kuparinen wrote:
> > > How can I get better speed (800+ Mbps) within NetBSD?
> > 2.) Please try to run "ttcp" with the option "-s 131072" to increase
> >     the socket buffer size.
> 
> Wouldn't net.inet.tcp.recv/sendbuf_auto set to 1 solve that?  Is
> there any reason it isn't the default?

It doesn't deal well with contention -- that is, if you have a large
number of sockets open, and run the system out of buffer space via the
autosizing, the performance effects can be unobvious and in some
cases just plain wrong.  So it's not always a great idea for server
systems, though it is a good default for clients.

-- 
Thor Lancelot Simon                                    
tls%rek.tjls.com@localhost
  "All of my opinions are consistent, but I cannot present them all
   at once."    -Jean-Jacques Rousseau, On The Social Contract