Not knowing but wondering: With Gigabit Ethernet and NFS in the mix, anything that gets latency out is a very good thing :-) and would improve performance.
MJM ----- Original Message ----- From: "Mike Silbersack" <[EMAIL PROTECTED]> To: "Storms of Perfection" <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Thursday, January 31, 2002 12:33 PM Subject: Re: Clock Granularity (kernel option HZ) > > On Thu, 31 Jan 2002, Storms of Perfection wrote: > > > I'm going to benchmark different network senarious with different options > > to see what I can get, and what works best. If someone wants to help me > > out, I could maybe write up a article about it? > > I don't think you'll end up seeing the performance improvements you're > looking for. The case where HZ=1000 is really useful is when using > dummynet; the more accurate scheduling is necessary for it to handle high > data rate pipes properly. > > The TCP stack, on the other hand, is perfectly happy with 10ms resolution. > Retransmission timeouts are only actually used when loss occurs on the > network, and 10ms is more than accurate enough for retransmission. (I > believe that retransmit timeouts are rounded up to 1 second, but don't > quote me on that.) The other timed events (keepalive timeouts, delayed > ack timeouts, etc) are also in good shape with 10ms accuracy. > > So, it's highly unlikely that you'll be able to observe a perceptable > difference in network performance except in really convoluted cases. > > Mike "Silby" Silbersack > > > To Unsubscribe: send mail to [EMAIL PROTECTED] > with "unsubscribe freebsd-hackers" in the body of the message To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-hackers" in the body of the message
