AGP Question

[CubanCorona]

A friend of mine just gave me an old Dell computer of his. The model name is XPS R450. The motherboard uses the old Intel 440BX chipset, and the AGP port is clearly an AGP 2x, 3.3 volt. I have a AGP4x video card here, but it doesn't seem to work in the AGP2x socket on this computer! I thought that AGP4x was backward compatible. Is there any way to make this work? If not, where can I get a video card with this AGP2x specification? Thanks!

Willow

 

[eklass]

agp 4x is backwards compatible with 2x, but 2x isn't compatible with 4x.. that's what you're thinking...


the mobo can be 4x and the vid card 2x, but not the other way around...

mobo >= vid card

 

[AndyHui]

Originally posted by: eklass
the mobo can be 4x and the vid card 2x, but not the other way around...

This is not quite correct. AGP4X and AGP2X are fully forwards backwards compatible for the card. An AGP4X card should be auto-switching voltage for 3.3V and 1.5V. AGP4X and AGP8X boards have compatibility problems.

The DELL Dimension XPS R450 should be using either an Intel Seattle SE440BX or Sun River SR440BX board. Both should be able to cope with the amp draw as those boards are not flagged as having AGP power problems.

Are you sure your AGP card works?

 

[Peter]

There are AGP4x-only cards; besides, most 8x cards aren't backward compatible to 2x anymore either.

Power budget is a matter of AGP specification revision level - AGP 2.0 boards have a much higher budget than 1.0 ones, _independent_ from what the supported transfer modes are.

 

[10k]

MY Leadtech GF4ti4200 AGP*8 works fine in my AGP 4 mobo. All AGP CARDS ARE BACKWARDS COMPATIBLE they have to be NUFF said

 

[Peter]

You not listening? AGP 8x cards are backward compatible to 4x and no further down.

 

[AndyHui]

Originally posted by: 10k
MY Leadtech GF4ti4200 AGP*8 works fine in my AGP 4 mobo. All AGP CARDS ARE BACKWARDS COMPATIBLE they have to be NUFF said

As Peter says (and he is just about always correct), AGP8X cards are only compatible down to AGP4X.

 

[Peter]

Normally. It seems some of ATi's are capable of stepping down to 2x too. What's for sure is that AGP 8x mainboards never do 2x AGP anymore.

 

[CubanCorona]

Thanks for all the help guys! Peter mentioned that some cards are AGP4X only, which would explain the problem here. The card I have is a VisionTek Geforce2 MX 64 MB. On amazon.com (which is where I originally purchased the card) it lists the interface type:

Interface: AGP 4x/2x

I suppose this means that it *should* be working. I'm going to check the card in another mobo which I know supports AGP4X. I'll let ya know what happens. Thanks again for all the help!

Willow

 

[JoeBaD]

How much performance do you lose putting an 8X vid card in a 4X mobo?

I'm thinking about putting a Radeon 9500 in a compaq AGP 4X box. Am I crazy?

 

[CubanCorona]

From what I've heard, the benefits of AGP8X right now are virtually unrealized.

There's actually a thread about it in this forum here.

Willow

 

[Lawranch]

How much performance do you lose putting an 8X vid card in a 4X mobo?

I think your processor/memory technology would be more important than 4x vs 8x. If you have an old CPU/motherboard you won't get the most out of a new video card.

And I have a 4x AGP Geforce 2 ti running fine on my wife's BX board. Try the card in another system, and make sure everything is tight.