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Questionable reference[edit]

The following reference: goes to a tutorial on 3d graphic design, it appears the site sourced doesn't contain any information on computer hardware. Real reference on PCI-X vs PCI-e would be preferable. —Preceding unsigned comment added by (talk) 07:27, 26 March 2008 (UTC)

Fixed this page has changed since the access date now has reference to archival copy at .Phatom87 (talk contribs) 16:05, 26 March 2008 (UTC)


I never really have seen a true PCI-X slot before. What uses it and where is it on wikipedia? PCI-X and PCI-e are separate things, so what is PCI-X then??? Bourgeoisdude 23:51, 17 April 2006 (UTC)

PCI-X is a computer bus, like PCI, and PCI Express. PCI-X came after PCI but before PCI Express. It was used on some server motherboards, but wasnt used in normal desktop computers. -- Frap 01:56, 16 May 2006 (UTC)

I have a DELL Precision Workstation with one PCI-X slot. Adaptec makes U320 SCSI RAID controllers that fit in that slot and I have one installed on my workstation. the PCI-X runs at 3.3v and the PCI Express runs at 5v... and the pin configuration is different so PCI Express and PCI-x will not interchange. —Preceding unsigned comment added by (talkcontribs) 20:03, 16 June 2006

Easiest to recognize are the slots on workstation boards, where the 133MHz ones are used made with a green plastic instead of standard white. (talk) 17:23, 20 October 2010 (UTC)

Slot photo[edit]

Could someone please add a photo of some board with PCI-X slot? I want this to be able to compare this slot with PCI and PCI Express. Thanks in advance. --CrazyTerabyte 14:19, 26 May 2006 (UTC)

See for instance .—Preceding unsigned comment added by (talkcontribs) 16:20, 16 June 2006
The slot is physically identical to a 3.3V 64 bit PCI slot, the change is the speed increase. Plugwash 01:52, 17 February 2007 (UTC)


133mhz*64bit is 8 gigabit per second(roughly), 66mhz*64bit is 4 gigabit per second (again roughly), normal PCI is 33mhz*32 which is 1 gigabit per second (again roughly). Also i was under the impression that all speeds beyond normal PCI were classed as part of PCI-X is this not the case? Plugwash 23:07, 15 June 2006 (UTC)

PCI has always had a 64-bit option. 66 MHz operation was first specified in PCI Revision 2.1. Higher speeds are PCI-X.

Ebichu63 10:39, 27 June 2006 (UTC)

This page says, "theoretical maximum amount of data exchanged between the processor and peripherals with PCI-X is 1.06 Gb/s, compared to 532 Mb/s with standard PCI". The small b implies bits per seconds and not bytes, but aren't these numbers byte numbers??? —Preceding unsigned comment added by Psprague (talkcontribs) 18:24, 27 September 2006
I agree with the previous post. If you take a look at the 133mhz*64bit equation above, that makes 133 thousand cycles a second, multiplied by 64 bits (8 Bytes!!). So, 133 thousand multiplied by 8 Bytes = 1,064,000Bytes (1.064GBytes - not bits). There are bit / byte errors in this Wikipedia entry. This has a significant impact on expected throughput (like nearly 10x!!) —Preceding unsigned comment added by (talkcontribs) 13:19, 6 October 2006

direction confusion[edit]

"PCI-X buses are unidirectional whereas PCIe buses are bidirectional" is exactly backwards. I think what is meant is PCI-X is only half-duplex (the data bus is implemented with parallel bidirectional signalling, which can only communicate in one direction at at time) while PCIe is full duplex (implemented with serial unidirectional signalling, i.e. separate transmit and receive traces, so there can be communication in both directions at the same time). 18:10, 25 July 2006 (UTC)kenf


Here you go. I've uploaded a very high res picture that i took with my CANON EOS 30D. You can use it as you want. —Preceding unsigned comment added by Spc01 (talkcontribs) 23:43, 7 October 2006

Plug a PCI-X card into PCI slot[edit]

A PCI-X card cannot, however, be installed in a PCI slot due to the edge connector configuration.
I inserted a PCI-X SCSI card (64-bit, 133M, universally-keyed) into a 32-bit PCI slot on an ordinary motherboard and it works.-- 09:37, 16 February 2007 (UTC)
I've corrected that, the important factors with all versions of PCI are the voltage keying and the physical space issue (e.g. whether there is anything on the motherboard that would block the overhanging of a 64 bit card). Plugwash 01:42, 17 February 2007 (UTC)
I can not see the correction. Did you just remove the sentence? It would be nice to have a couple of sentences about plugging a PCI-X card into PCI slot, for completeness. —Preceding unsigned comment added by (talk) 00:56, 21 July 2009 (UTC)
I've also used an Adaptec 21610SA PCI-X SATA RAID card on a 32-bit PCI slot, and it worked fine. Seems both this article and Conventional PCI article now refer to this LaCie page for the fact that PCI-X doesn't work in PCI, but I figure that page must be wrong then. E.g. this page from PC Magazine seems to apparently correctly say that "PCI-X cards will run in PCI slots, but at the slower PCI rates". Anssi (talk) 11:49, 23 December 2011 (UTC)

32-bit PCI card, in a 64-bit PCI-X slot?[edit]

Does a 32-bit regular PCI card work in a PCI-X 64/133MHz slot? 22:50, 20 April 2007 (UTC)

Yes with a couple of caveats. Firstly the card must suport 3.3V and have the 3.3V notch which a large proportion (more than half in my experiance) of 32 bit cards don't. Secondly it will also slow the entire bus down to whatever maximum speed the card supports. Plugwash 13:55, 23 April 2007 (UTC)

Must PCI-X bus support all PCI bus speeds, e.g. 33mHz?[edit]

A lot of server/workstation motherboards have PCI-X slots listed as 133/100mHz. Can these slots "clock down" to 33mHz, so that cards that can only run at 33mHz work? Or do they only run at what is listed in the specification, e.g. 133 or 100 mHz? 21:50, 23 April 2007 (UTC)

Background section needs cleanup[edit]

There's info repeated two or three times in it. Could be about half as long. —Preceding unsigned comment added by Bizzybody (talkcontribs) 08:15, 8 October 2007 (UTC)

Yes it looked like paragraphs or sentences were duped / edited once or twice then shuffled. This has been cleaned up, along with some minor copy/link editing. -Onceler 08:23, 26 October 2007 (UTC)

PCI-X "Backward Compatible"??[edit]

I'm sitting in front of three servers with PCI-X slots, and there's no way you could put any PCI card into any of them. There's a key in the way. What's the source of this backwards compatibleness sentence? (talk) 11:16, 9 March 2010 (UTC)

I also have various raid controllers that will not fit on a normal PCI slot due to voltage keying.

They will neither fit 32 or 64bit slots. One is a HP Smartarray (model 6504 i think). The other one is a ICP Vortex ICP9014RO. Both got the PCI-X 133 logo. So I think that everything from 133MHz is not backward compatible. (talk) 17:30, 20 October 2010 (UTC)

The original (and still the most common) variant of PCI was 5V 33MHz. Higher speeds of PCI slot (including PCI-X) are always 3.3V. 5V and 3.3V cards are keyed differently. Most modern cards are universal voltage and can work in either voltage of slot but you do still see single voltage cards. Plugwash (talk) 21:30, 20 October 2010 (UTC)

Phaseout of PCI-X in Favor of PCI-E: Is a citation really needed?[edit]

I notice the final sentence of the summary is marked with [citation needed], but I feel as though this falls into the category of subject-specific common knowledge. Thoughts? See: Wikipedia:When to cite. — Preceding unsigned comment added by CDel921 (talkcontribs) 17:31, 9 November 2012 (UTC)

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