Comments on: PCI vs. PCI-X vs. PCI Express

By: Jon

Jon — Thu, 20 Aug 2009 20:35:20 +0000

There were some experimental 233mhz PCI-X cards made, but they found that any higher frequency was simply not going to work because the distance for the wave got too short.

This is all kind of moot now, of course, since PCI-E has completely taken over and is currently working towards the 2.0 standard (3.0 apparently has been delayed until 2011 now)

By: darkness

darkness — Fri, 20 Jun 2008 02:44:06 +0000

As far as I know, no, you can’t put PCI-X into a PCI-E slot of any type.

By: Nick

Nick — Thu, 19 Jun 2008 23:37:43 +0000

This is a great article. I’d like to see another on PCI/PCI-X/PCI-E commpadibiliy. I’ve been researching for a year in preparation for building my own computer for about a year. I’ve found the perfect motherboard but it is running low on PCI slots. It was made for 3-way nVidia SLI so it has… 3x PCI-E x16 slots, 1x PCI-E x1 slot, and 2x PCI slots. So i really want 2 PCI-E x16 video cards, 1 PCI to USB PCI card, 1 PCI to wireless network card, and 1 PCI-X RAID 0/1 controller card. That means I have one spare PCI-E x16 slot left and need to put in my PCI-X RAID card. SO HEARS MY QUESTION!!! Can you put a PCI-X card into a PCI-E x16 slot? Please email me. again great article. Would like to see more.

By: xmoe

xmoe — Mon, 04 Dec 2006 14:32:16 +0000

AFAIK - PCI-X is backwards compatible, except where it is 3.3V … you can have PCI cards that are 5V only … or ‘universal’ cards that should work in any PCI slot - that is 5V or 3.3V … I think the majority (90%) of PCI cards are universal, but then the devil is in the details and what you actually have.

Also I would not characterize PCIe bandwidth as “2GBps” when its actually only 1GBps ‘full duplex’ .. certainly this has some nice performance boosts over PCI, but its not like you can push 2GBps in one direction … its simply like ethernet 1Gbps (bits - yes) full duplex … I think they should keep it like this for any other serial bus.

By: Gary Quiring

Gary Quiring — Wed, 22 Nov 2006 12:41:52 +0000

The line “PCI-X is backwards compatible with PCI, and that goes for both slots and devices.” is not always true. I have a v20Z Sun server that uses PCI-X and it won’t physically fit a PCI card. The slot is backwards preventing them from fitting. PCI-X compatible cards fit fine.

By: Andy

Andy — Sun, 21 Aug 2005 00:37:07 +0000

“A 133MHz bus can only support one device. A 100MHz bus can only support two devices. I believe a 66MHz bus can support four devices.” Hmm… Sounds like the VLB of the PCI world.