What is this "PCI express" thing?

[J. Clarke]

Is this a new PCI technology not specifically designed for AGP slot, but
for
all other components such as "sound card", "ethnernet card" that delivers
faster buss-speed than that of AGP 8X?

If that's the case, is it wrong to assume that all sound and ethernet
cards have to be re-desinged to take advantage of this new PCI express
technology? Since PCI express provides faster buss-speed than that of AGP
8X, would it be accurate to assume that AGP video cards might be obsolete,
if not this or next year, some time in future when this PCI express
becomes more common and stable?

PCI Express is primarily a marketing gimmick aimed at forcing users who
upgrade one component to upgrade everything, and possibly secondarily at
damaging Intel's competitors who having developed processors and chipsets
that kick Intel's butt in every aspect of performance will now be forced to
put that effort on the back burner to play catch-up with Intel's new bus
games.

In the real world, as implemented on current machines its utility is
minimal. If you want to find out what Intel _really_ thinks read the specs
on their chipsets that support PCI Express and you'll find that for their
internal functions they use PCI-X instead.

PCI Express, according to its advocates, will make motherboards and the like
simpler and cheaper. Given current motherboard prices there isn't room for
much more cheapness, so that argument fails. They claim that it will make
boards "simpler" because PCI Express uses one high-speed pair where regular
PCI uses parallel traces. They neglect the fact that PCI Express even in
the lowest speed variation uses several pairs, and the fact that it is
point-to-point and not a bus so instead of one set of traces that serve 8
slots, with PCI Express each slot needs its own set of traces. They claim
that it will improve performance--this might actually happen when disk
performance improves a good deal--right now the only thing you are likely
to stick in a PCI slot that is restricted by PCI is a gigabit Ethernet
board and that's only restricted if you have something else in the machine
that can fill a gigabit pipe, and unless you have a high-end server with a
huge drive array that it not the case.

It will not improve video performance for most users in the foreseeable
future--while PCI Express 16X is a faster interface than AGP 8X (and note
that the "16X" and "8X" there refer to two different things--they are not
directly comparable measures of performance) there is no indication that
AGP 8X gives noticeable better performance than AGP 4X, so more speed in
that interface seems wasted. While there are some schemes to parallel two
video boards, right now they are not going to accomplish much because there
are no motherboards shipping and no chipsets announced that will have
support for more than 1 16X PCI-E slot, and the few that can support a 16X
and an 8X are dual-Xeon boards.

Nonetheless it is something that Intel is going to cram down your throat
whether you like it or not, so you may as well get used to it.

 

[Glitch]

I agree in almost everything you said but you said one thing wrong.

While there are some schemes to parallel two

video boards, right now they are not going to accomplish much because there
are no motherboards shipping and no chipsets announced that will have
support for more than 1 16X PCI-E slot, and the few that can support a 16X
and an 8X are dual-Xeon boards.

This is wrong because Intel already anounced Tummwater that will support two
PCI-E 16x slots,Tummwater is coming in Q1 or 2 of 2005.
nVidia(personally I don't like them,I prefer ATI) also anounced its SLI
interface which would enable coupling up two PCI-E cards.

 

[J. Clarke]

I agree in almost everything you said but you said one thing wrong.

While there are some schemes to parallel two

This is wrong because Intel already anounced Tummwater that will support
two PCI-E 16x slots,Tummwater is coming in Q1 or 2 of 2005.
nVidia(personally I don't like them,I prefer ATI) also anounced its SLI
interface which would enable coupling up two PCI-E cards.

The spec sheet for the chipset is on the Intel site. According to that spec
sheet it does _not_ support two PCI-E 16x slots. It has 24 PCI Express
lanes that can be configured as 1 16x and 1 8x or 1 16x and 2 4x.

As for nvidia's "SLI", first, it's not "SLI" in anything but name, it is two
boards with a video combiner and Alienware has something similar coming
that works on the same principle.

And if you will bother to review the discussion on the
alt.comp.periphs.videocards.nvidia you will find that this has already been
beaten to death.