Fwd: Re: Differences between constructive anddestructivecriticism

[Chris Pressey]

On Sat, 12 Mar 2005 18:54:12 -0500
EM1897 at xxxxxxx wrote:

> Processor speeds have "hit a wall", which means that they
> can't get much faster. So the best way to get more 
> performance is to increase support for MP. My point was
> that current 'BSD OSes don't utilize MP very well, so 
> the best price/performance is with UP.

Yes, at the present time, it probably is.

> I find the empirical
> evidence somewhat undeniable, but apparently the notion
> is irritating to people. Why do I care if other people
> waste their money? That, I can't answer. 
>
> The "other" point, was that if I were to accept the premise
> that opterons are empirically faster than P4s, you can't
> possibly get better performance on a PCI bus than you do
> on a PCI-X bus, so quoting opteron MBs that don't have a
> PCI-X bus is not quoting a comparable system, assuming
> that networking is an important component of why you 
> are buying a system in the first place.  It seems that
> there are many that find this notion irritable as well, 
> even though all of the empirical evidence is that running
> NICs on a faster bus substantially decreases the CPU load
> of the system.

This part (which I still have a bit of a hard time following) is
probably what confused me about when you said UP "hit the wall";
obviously if the bottleneck is not the processor, then that's not the
wall that's being hit!

> Now if someone actually had evidence to the
> contrary, it might be an interesting discussion. But what
> we have is a bunch of evidence in the form of easily 
> duplicatable measurements,

I must have missed them... which message are they in?

> and a mob with no evidence at
> all, and apparently no experience even using the bus 
> since they think its bleeding edge (even though its
> been the dominant but for many years, telling me I'm crazy. 
> So the only possible conclusion is that there isn't any intelligent
> life amongst the mob members. Since both Matt and Joerge seem to
> consider a fast bus  a "strange requirement", one has to wonder how
> dragonfly will ever be optimized for networking?

Well, hopefully someone with some sense will at some point send in some
patches that will allow DragonFly to support PCI-X :)

> Hope that clarifies things.

Yes, quite a bit.  Thanks.

-Chris