[geeks] Carly's Gone!!!

Charles Shannon Hendrix shannon at widomaker.com
Mon Feb 14 11:52:22 CST 2005


Thu, 10 Feb 2005 @ 21:24 -0800, Francisco Javier Mesa-Martinez said:

> On Thu, 10 Feb 2005, Charles Shannon Hendrix wrote:
> 
> > Well, PCI wasn't supposed to have been exposed as a mezzanine bus at
> > all, but a chip interconnect.  It wasn't good enough for a system bus,
> > and got morphed into a mezzanine bus.
> 
> Huh? Where did you get that information? Never heard of a "mezzanine bus"
> care to explain? 

Mezzanine bus means external bus, something outside of the system
busses.

> PCI was never intended as a chip interconnect, again... 

Yes, it was.

The base technology of PCI was created *BEFORE* the the search for a
replacement for EISA and MCA external busses.

Intel used existing work to create PCI and present it as a
consideration.

> > I thought PCI-X was basically just an improved mezzanine bus, not a
> > motherboard I/O subsystem.
> 
> I think you misunderstood PCI-X is a fast PCI, 

Actually, I didn't misunderstand, I read specifically that in multiple
references.  Maybe they are all wrong, but you can figure that out for
yourself.

HP, Compaq, and IBM claim to have created PCI-X, and Compaq says this:

    Q.  What is PCI-X?

    A.  The PCI-X protocol is a high-performance extension to the
	existing PCI Local Bus. PCI-X provides the increased bandwidth
	and bus performance needed to address the escalating I/O demands
	from enterprise applications, such as Fibre Channel, Ultra3
	SCSI, SAN interconnects, and Gigabit Ethernet.

The rest is here:

    http://h18004.www1.hp.com/products/servers/technology/pci-x-qa.html

HP's FAQ on PCI-X is here:

http://h18004.www1.hp.com/products/servers/technology/pci-x-enablement.html

According to HP and Compaq, PCI-X is a backward compatible extension to
PCI.

Also see http://www.pcisig.com, which repeats the same.

PCI-X is a backward compatible upgrade to the PCI bus.

> > I didn't realize it was supposed to be a whole system thing.
> >
> > Right now it seems like it isn't used for anything except graphics
> > cards.
> 
> Haven't seen any PCI-X gfx cards at all... so I dunnot what you are
> talking about.

Sorry, I was thinking of PCI-E.







-- 
shannon "AT" widomaker.com -- ["Meddle not in the affairs of Wizards, for
thou art crunchy, and taste good with ketchup." -- unknown]



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