latency Re: ide: Assuming 33MHz

[Alvin Oga <aoga@ns.Linux-Consulting.com>]

hi ya kirk

On Tue, 29 Jun 2004, Kirk Strauser wrote:

> On Monday 2004-06-28 09:11 pm, Alvin Oga wrote:
> 
> > if your cpu is running at say less than 75% load, your system is NOT being
> > used to the fullest extent for the $$$ you paid :-) 
> 
> Exception: we spec our webservers for *latency*, not *throughput*.  Even if 
> we only get 20 hits per day, I want them to be served quickly.

for best latency performance:
i'm assuming that you have 15K rpm scsi disks or even 10K ide disks to
eliminate disk latency  and one ide disk per ide cable and .. 
and you're using fastest speed ddr memory your mb supports
and tons of memory in the mb, 2GB seems to make some systems run
"10x faster" since its all in memory instead of disk
and you've tuned nfs and the tcp stack to minimum latency for
fastest delivery across the wire

and yeah ... "one hit" downloading one cdrom can be a big problem :-)

but if they other end is on a 56K dialup, it wont matter that we can
deliver content in 10^-99 seconds

and yes .. lots of fun tuning to optimize performance vs costs
vs delivery at the user :-)

and after all is said and done, it'd have been better to spend the same
$$$ on a 2nd full "live hotswap backup" ( or load balancing ) instead
	- the one fully optimized server dies, and your latency 
	just went to !@#$%% .... but if you have one on the east coast
	and another clone on the west coast, than all is "good"

and more smileys ... :-)

c ya
alvin