[rescue] Any Minneapolis area listers ?

[Jochen Kunz]

On Thu, 11 Jan 2007 09:41:51 -0500 (EST)
Ethan O'Toole <ethan at 757tech.net> wrote:

> Server boards have multiple busses, and you could get cards of
> different types.
>
> Oh yea:
> http://users.757.org/~ethan/pics/geek/computer_stuff/soundcard_champion/
> 19 pci slots, 5 busses, 1 box. Booya.
Useless for things that need lots of IO bandwith. The intel 21152 chips,
that you can see on one of the pictures, are PCI-to-PCI bridges. So you
have multiple PCI busses, but they hang all off a single root PCI bus
and share the bandwith of that bus. Depending on that root bus your
total aggregate IO is limited to maybe 120 MB/s for 32 bit / 33 MHz PCI.
If that root PCI bus is 133 MHz PCI-X it may be better, but not ideal.

Somthing like a HP9000 C3000 is much smarter build. It has multiple
PCI-host bridges. So you get a bunch of really independent PCI busses
that connect to CPU and memory via a really fast front side bus.
--


tsch|_,
       Jochen

Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/