So, as the title says, what is PCI-X? I cant seem to find much info about what it is, or what kind of cards are commonly used with it. This question came up when I was casually scrolling ebay, and found a Dell Precision 490 that has two of these PCI-X expansion slots.
Thanks for the info.
133mhz 64-bit pci 3.3v (some went up to 533mhz)
pci x cards will often work in 32 bit slots though
Yep it's PCI-64 pretty much like ISA-16 versus the 8 bit original (or nowadays, people using the wrong abbreviation for pci express)!
In general it was used for "professional" cards like SCSI (the only one I've seen in person), gigabit-compatible ethernet, and the like...
I’ve got a PCI-X Matrox Parhelia, but typically the cards you’d find for PCI-X would be RAID adapters or multi-port Gigabit network adapters.
Not much info? There's a Wikipedia article for starters that explains the basics:
https://en.wikipedia.org/wiki/PCI-X
PCI-X, short for Peripheral Component Interconnect eXtended, is a computer bus and expansion card standard that enhances the 32-bit PCI local bus for higher bandwidth demanded mostly by servers and workstations.
The slot is physically a 3.3 V PCI slot, with exactly the same size, location and pin assignments. The electrical specifications are compatible, but stricter.
3.3 V and 5 V keying of 64-bit PCI cards (both PCI and PCI-X). While most 64-bit PCI-X cards are universal and are backward compatible with common 32-bit 5 V PCI slots, PCI-X slots are 3.3 V and will not accept 5 V-only PCI cards.
Most 32-bit PCI cards will function properly in 64-bit PCI-X slots, but the bus speed will be limited to the clock frequency of the slowest card, an inherent limitation of PCI's shared bus topology.
Even if it would work, installing a 64-bit PCI-X card in a 32-bit slot will leave the 64-bit portion of the card edge connector not connected and overhanging, which requires that there be no motherboard components positioned so as to mechanically obstruct the overhanging portion of the card edge connector.
dionb wrote on 2023-01-31, 07:54:Not much info? There's a Wikipedia article for starters that explains the basics:
https://en.wikipedia.org/wiki/PCI-X
Also...
Discussion of 64-bit PCI vs. PCI-X. Confusion abounds!
... those discussions likely cover a good portion of what is relevant to most VOGONS users.
There isn't a ton of discussion on there about them, but I'd say that's mainly because there is almost nothing gaming related that is impacted by the existence of PCI-X in any way. The boards that use it are usually server or workstation oriented, so often have compromises that don't make sense to double as a retro gaming system. So you end up with boards that have weird features or quirks (at least as far as a home gaming PC is concerned) and slots that may as well just be standard PCI slots. Also, many PCI-X boards don't even have AGP because they have some kind of integrated video.
As the last thread above mentions, one somewhat interesting use for PCI-X for retro gaming is for experimenting with the 66Mhz PCI BUS in an overpowered Voodoo 5 PCI system. I don't really have any experience with that however, so I'm not sure how much it matters or in what boards\configurations it can actually be used. The tiny bit of info I just found on the subject basically says that a V5 on a 66Mhz PCI-X slot is faster than a standard 33Mhz slot, but is not as fast as AGP. Not sure if that's always the case or not.
That's about as niche as things get around here though. Hence the lack of PCI-X discussion. 😀
Now for some blitting from the back buffer.
Ozzuneoj wrote on 2023-01-31, 08:15:[...]
That's about as niche as things get around here though. Hence the lack of PCI-X discussion. 😀
There's always Parhelia Matrox Parhelia 256 PCI-X Performance
(cheaper than a V5 too...)
I am running a V5 PCI Mac on pci-x slot. It's actually quite the same speed as on a regular agp slot. As far as i am aware the voodoo does not use any agp specific instructions anyway.
My file server for years ran PCI-X SATA RAID cards, first the RocketRAID 1820A, then the 2220. (It now uses a 2320 with PCIe x4)
Is this too much voodoo?
Guessing your in the same boat as I was few years ago.
I had a server of some type that I was looking to upgrade just for the sake of upgrading.
As others have said Network and RAID cards are the cheap options, neither of which interested me.
Graphics was the most interesting option but PCI-X cards were overpriced meaning you could get faster PCI cards for cheaper.
I've a few of the slightly newer Precision T5500's which have PCI Express if you wanted to look for an alternative
Ryccardo wrote on 2023-01-31, 06:32:Yep it's PCI-64 pretty much like ISA-16 versus the 8 bit original (or nowadays, people using the wrong abbreviation for pci express)!
I think it's more a repeat of EISA: mostly confined to servers, pushed by a group of OEMs as a stop-gap until the next generation of IO turned up. EISA is to PCI as PCI-X is to PCI Express.
I thought IBM was born with the world
Some 32-bit PCI cards can run at 66 MHz or higher so you will still get a performance boost from plugging them into PCI-X slots.
ETA: But be careful what cards you put on the PCI-X bus. A single 33 MHz card will drag the speeds of all other cards down to that level.
ETA2: Related discussion
Is this too much voodoo?
chinny22 wrote on 2023-01-31, 16:54:Guessing your in the same boat as I was few years ago. I had a server of some type that I was looking to upgrade just for the sa […]
Guessing your in the same boat as I was few years ago.
I had a server of some type that I was looking to upgrade just for the sake of upgrading.
As others have said Network and RAID cards are the cheap options, neither of which interested me.
Graphics was the most interesting option but PCI-X cards were overpriced meaning you could get faster PCI cards for cheaper.I've a few of the slightly newer Precision T5500's which have PCI Express if you wanted to look for an alternative
Pci to agp adapter? In the 66 mhz pci x slot? (I think you can signal 66 mhz at one of the pins
Here's a fun one: The Matrox Parhelia with the 64-bit PCI connector isn't PCI-X. We can tell this a few ways:
1. The big chip on the back is a PLX PCI6154, which is a plain old 66MHz 64-bit PCI bridge
2. PCI-X cards have a signal called "PCIXCAP" on pin B38 which is tested by the source bridge at power-up to determine if a PCI-X device is plugged in. The mainboard has a pull-up resistor on this signal. PCI cards ground this pin, 133MHz PCI-X cards have a decoupling capacitor on the pin so it goes to the pull-up voltage, and 66MHz PCI-X cards have a 10K ohm resistor to ground so the signal is part way between high and low. (So sayeth the good book "PCI-X System Architecture" by Tom Shanley/MindShare Inc, pages 58-59.) On the Parhelia this pin is grounded, indicating it's normal PCI.
3. Should be able to check the Capabilities registers of the Parhelia for a PCI-X non-bridge device entry, haven't done this because I'm too lazy.
Well I had fun anyways.
PCI-X is called PCI eXtended.
~ At least it can do black and white~
My experience with PCI-X is mostly about some LSI HBAs. The PCI-X slots can indeed provide bandwidths capable of saturating SATA2 (300MByte/s) speeds so you can run decent SSDs on them.
Theoretically PCI-X can be used for many things just like PCI, but unfortunately it only saw very limited use cases. Things like USB 3.0 should be possible on PCI-X but no one has ever made such cards, as by the time USB 3.0 came out (2008) PCI-X has long been superseded by PCIe.
On the other hand, PLX had a bridge chip called PEX8114 which can be used to convert between PCI-X and PCIe (x4), though so far I only found it being used as a forward bridge on some signal acquisition cards that connects to the PC via PCIe x4 interface. While PEX8114 can be configured as a reverse bridge (that connects to the PC via PCI-X) just like its PCI counterpart (PEX8111/PEX8112), no one's making such an adapter for PCI-X boards, even though a development kit (RDK) for PEX8114 in reverse bridge mode existed from what I could find on google.
pancakepuppy wrote on 2023-02-01, 01:56:Here's a fun one: The Matrox Parhelia with the 64-bit PCI connector isn't PCI-X. We can tell this a few ways: 1. The big chip on […]
Here's a fun one: The Matrox Parhelia with the 64-bit PCI connector isn't PCI-X. We can tell this a few ways:
1. The big chip on the back is a PLX PCI6154, which is a plain old 66MHz 64-bit PCI bridge
2. PCI-X cards have a signal called "PCIXCAP" on pin B38 which is tested by the source bridge at power-up to determine if a PCI-X device is plugged in. The mainboard has a pull-up resistor on this signal. PCI cards ground this pin, 133MHz PCI-X cards have a decoupling capacitor on the pin so it goes to the pull-up voltage, and 66MHz PCI-X cards have a 10K ohm resistor to ground so the signal is part way between high and low. (So sayeth the good book "PCI-X System Architecture" by Tom Shanley/MindShare Inc, pages 58-59.) On the Parhelia this pin is grounded, indicating it's normal PCI.
3. Should be able to check the Capabilities registers of the Parhelia for a PCI-X non-bridge device entry, haven't done this because I'm too lazy.
Well I had fun anyways.
Yeah the PCI-X seems to be more of a classic marketing thing when the card is actually 33 - 66 mzh PCI 64.
Featuring 256 MB of DDR memory, a PCI-X interface designed for both 33 and 66 MHz buses, as well as Y/C and composite input and output support, the Parhelia PCI boasts the industrys most advanced multi-display technologies
66 MHz bus for PCI-X : check
33 MHz bus for PCI-X : wha?
I'm only commenting on the card I have the Matrox Parhelia PCI 256MB PH-P256.
