Is a agp 1 or agp 2 motherboard will accept agp 4 or 8 video card?

[lavoieduchrist]

Hello everyone,

i have a issue with my old system, it's setup with a old Asus P3B-F motherboard which is suppose to be compatible agp 1 and 2. My problem is i have something broken in it and now i cant boot up my comp...and thre is no signal between my monitor and my system....i thought that was my video card, but it was doing the same thing with a new Radeon 9200 which a barrowed from my father.

Is a agp 1 or agp 2 motherboard... accept agp 4 or 8 video card as well?

thanks

 

[Matthias99]

NO.

1X and 2X AGP use a different signalling voltage than 4X/8X AGP.

 

[tungtung]

Matthias99 Not entirely true.

Check this thread or this ATI link out.
I've posted a while ago that I managed to get a Radeon 9800SE working on an old AGP 2x motherboard. If you look at the chart Radeon 9200 should be compatible with AGP 2x.

I'm quite sure that if it's not compatible you won't be able to plug it in.
However might want to double check the manual for the card first.

 

[Matthias99]

I didn't think that's what he was asking... a 4x/8x card is not the same as a 1x/2x/4x or 2x/4x/8x card. But yes, some cards are compatible with both. Checking the manual is always a good idea.

 

[VirtualLarry]

Many/most modern mobos these days only support a 1.5v signalling voltage for the AGP port. Plugging in an older 3.3v AGP 1X/2X card will likely fry the mobo, and maybe the card. But as for plugging an AGP 4X/8X card into an AGP 1X/2X mobo, I don't know. I had always assumed the same, that "bad things will happen". But I've also read about some people using AGP R9200s, which are normally AGP 8X-capable cards, in older AGP 1X/2X mobos. So I dunno. Luck? Or is there something special about most R9200s that they will work in those older boards? (Kind of intrigues me, because I have a 9200 AGP, and it would be cool to stick it in an older 440BX system when I upgrade, but I'm still too afraid that it would fry something.) It could be because the chipset used on the R9200, is apparently also PCI-compatible (as they sell R9200 PCI cards), and PCI normally uses 3.3v (3v?) signalling voltages, so perhaps the R9200 is "special" that way, and is 3.3v-tolerant or compatible somehow.

Edit: Interesting, I looked at tungtung's second link to ATI's site, and it appears that some of their cards that sport an "AGP universal connector", also support AGP 2X slots and a 3.3v signalling voltage. Good to know, thanks. Looks like RTFM is a good idea. (Also, according to that chart, the R9200 is indeed unique, it supports both AGP 2.0 and AGP 3.0 protocol, and is the only listed ATI AGP card capable of doing so.)