If an AGP slot isn't keyed for 1.5v or 3.3v then is it universal?

[avi85]

The question is in the title.

 

[Captante]

It should be ... however the card & motherboard will both fry if by chance its not, so take the time to find out... what type of card are we talking about? (chipset, brand name & model number)

 

[avi85]

Originally posted by: Captante
It should be ... however the card & motherboard will both fry if by chance its not, so take the time to find out... what type of card are we talking about? (chipset, brand name & model number)

the card is an ATI rage pro 2X AGP,
it's for a friend, he has an old willamette that he wants to use for office and stuff but it doesn't have a video card, and I have this old one hanging around so I just need to find out if it's compatible...

The card seems to be keyed for 3.3v (that's AGP 1.0, right?) and the mobo is not keyed at all (anything will fit), if I find a manual for the mobo then I should just see if it supports AGP 1.0?

 

[Peter]

You're mixing AGP standard revisions (1.0, 2.0, 3.0) with transfer modes (1x, 2x, 4x, 8x) and their signalling voltages.

Now, slot keying. This is solely (!) for supported signalling voltage - 3.3V, 1.5V, or both (no key).

Next, modes. 1x and 2x mode are 3.3V, 4x and 8x are 1.5V.

Finally, standards. AGP 1.0 defined 1x and 2x modes. AGP 2.0 introduced optional (!) 4x mode, and raised the power budget for the card. AGP 3.0 added 8x mode, and made support for 1x/2x modes optional.


Thus, the mix. If the mainboard says "AGP 1.0", then it's 3.3V only. If it says "AGP 2.0" it might still be 3.3V only - check the slot keying.

 

[Captante]

What Peter says is correct ... find the specs for the motherboard you are using to see which version of AGP it has, note that if you can't find the AGP version but its AGP 2x you should be fine while 1x could still be a problem. Also to the best of my recollection all of the Rage Pro cards are 3.3 volts.

 

[Peter]

Even if things look like they fit, you need to take a bit of extra care with that old stuff from the transition days.
In particular, when Intel brought the first 1.5V-only chipset (845? Can't really remember), several mainboard models were nonetheless fitted with "universal" (unkeyed) AGP slots. Plug a 3.3V card in one of those, and you'll get a warning beep at best - and smoke at worst.

 

[Ronin]

Easier way if you really don't wanna worry about it:

Use a PCI vid card.

 

[avi85]

Thanks for all the help, but it turns out the mobo is dead, so he doesn't need it in the end, but thanks for the responses!!!