ole abit

November 18, 2005 4:59 PM

I need a new video card for my old PC, with an Abit kt7-raid (which has AGP 2x/4x support). Will any AGP graphics card work? Any AGP 4x or 2x?

*sigh* four years ago I would have been able to answer this question my self, but I could care less about PC hardware these days, I just want to be able use my computer comfortably again

The graphics card developed a very strange analog problem, causing very low contrast. I assumed it was the monitor, but the image was the same on an entirely different monitor. It's very irritating to use the machine (I'm actually at work right now).

Are all AGP graphics cards compatible with all AGP slots? Do some cards require more modern versions of the interface? What's the deal?

posted by delmoi to computers & internet (4 comments total)

It looks like the main problem is going to be voltage settings. From the manual for the KT7-Raid card, it looks like the slot supports 3.3v or 1.5v AGP 1x/2x/4x cards. My guess is you should be safe with any 4x card, and you could possibly use some 8x cards as long as they support the universal version of the AGP 3.0 standard.
posted by curse at 6:00 PM on November 18, 2005

AGP cards (if they follow the spec) and slots are keyed by power, so if a slot cannot handle a given voltage, it should be impossible to insert a card that requires that voltage. If the notches in the card's connector line up with the bars in the slot, it'll be compatible. If the card has two cutouts in the connector, it's a "universal" card, able to work at either 3.3V or 1.5. AGP 8X uses .8V, but it keys at (and is required to boot up at) 1.5V -- if there isn't .8V power available, the card runs at 4X.

Bus speed is negotiated. The card (at 1X) asks the northbridge controller what speeds it can handle, then uses the highest speed that both are capable of.

Almost all 4X cards made in the last five years are universal.
posted by eriko at 6:33 PM on November 18, 2005

Hmm... I just bought a random board at best buy (the cheapest one they had) and it worked.

Thanks for answering my questions anyway :P
posted by delmoi at 7:13 PM on November 18, 2005

Did you check the video settings? Contrast issues pretty much do not happen in video cards on the physical level except for a bad connection between the monitor/card. You could try removing the drivers and reinstalling to set all settings back at normal. Oh well, you bought another card anyway.
posted by Dean Keaton at 1:26 PM on November 19, 2005