Subject: Re: Latency difference between fifo and pfifo_fast

From: Stephen Hemminger <[email-masked]>
Date: Wed, 7 Dec 2011 15:49:07 -0800

=
> > Is this a shared network? TOS won't matter if it is only your
> > traffic.
> > 
> > There are number of route metrics that you can tweak to that can
> > reduce TCP slow
> > start effects, like increasing the initial cwnd, etc.
> > 
> It is a private network dedicated only to SAN traffic - a couple of SAN devices and some virtualization hosts - John

Therefore unless your switch is shared, playing with queueing and TOS
won't help reduce absolute latency.
You maybe able to prioritize one host or SAN over another though.