PCI compatibility of old PCI chipsets and "newer" GPUs?

[eccerr0r]

I could have sworn my PCI ATI Radeon 9250 was working, but when I stuck it in an old 82430TX P5 board, it didn't work... is this expected?

I suppose I'll need to test it in a AGP board to see if it works or not, but this struck me as weird.

[eccerr0r]

hmm. nope, he's dead, Jim.
Or at least they don't like the BX board either.

[stj]

there are several revisions of pci like there are of agp.
no, i dont know the details

one other thing, be wary of any card salvaged from a powerPC based mac,
they could run the pci at double-speed!

[eccerr0r]

Yeah there was a pci 2.2 and 2.1 that I recall that was an issue where the pci2.2 required 3v3 on the bus, the older 2.1 all had LDOs on 5v to power 3v3 devices or something like that. But I think these were all 2.1 or older, I don't recall ever getting many 2.2 cards.

[stj]

also any card sold for a mac had a different bios.
those need to be re-flashed with the pc version.
i had a bunch of Adaptec scsi cards like that - seller thought they where dead, just needed a bios change.

[stj]

hmm...
why does it have 2 keyways?
https://www.techpowerup.com/gpu-specs/radeon-9250.c45

ah yes, it's AGP

[m1ch43lzm]

Test on the AGP system with both AGP and PCI cards installed, set the BIOS to "Init display first" AGP
Monitor connected to the AGP card of course...

Boot into the OS and check if the PCI card is detected there

As for 3.3V/5V, the slot is keyed differently, you either have a 5V card, or universal 3.3v/5V
None of the PC motherboards I have (dead or working) have 3.3V 32 bit PCI slots

5V PCI 32bit


Universal 3.3V/5V PCI 32bit