RE: Any serious production servers yet?

[Danial Thom <danial_thom@xxxxxxxxx>]

--- James Mansion <james@xxxxxxxxxxxxxxxxx>
wrote:

> >A dual-core 2.6 Opteron is about US$1079.
> whereas
> >a single core is about $460. So for about
> $200.
> >more I can build 2 2.6Ghz systems that give me
> a
> >lot more bang for my buck than 1 dual-core
> >system.
> 
> Well, the bleeding edge is always at a premium.
> But you mention a wall.  A wall doing what?
> Single threaded monte-carlo?  Single postgres
> query?
> 
> Almost any real-world load that will stress
> a modern server box comes from multiple
> requests.
> 
> As for pf performance - who the hell cares? 
> Are
> you routing between two 10GBit LANs?

Frankly I don't care about pf performance, but
your comments indicate your ignorance as to how
it performs under load. pf will barf on many real
networks pushing a lot less than you think,
depending on the complexity of the ruleset.

> 
> If you're using that much CPU, then if you care
> what OS you're using, your app is badly
> written,
> cos you should first avoid entering the kernel
> anyway as much as you can.


Ah, from the mouths of babes (or people who live
in tiny caves)!

If your network is pushing 300-500K pps its nice
to have a firewall or security device or router
that can handle it. And those filtering/network
functions don't benefit much from MP. The "wall"
is what such a box can handle with the fastest
processor available. Typically MP doesn't scale
well for such APPs, as the overhead associated
with threading the kernel slows the raw
performance more than is gained by having
multiple processors. Getting past the wall would
be good, but if the trade off is being able to do
some other stuff with the box simultaneously, the
capacity can't diminish too much, because once
your traffic levels are past the wall you are in
trouble. 

That is the "Wall" for people who are on real
networks. You could always count on the wall
advancing as our buddies at AMD and Intel
increased the GHZ. Now we're going sideways, and
many can't afford to have the wall regress to
accommodate smoother audio performance.


DT

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