Further AGP confusion

[996GT2]

I posted a thread before about my Dell Dimension 4100's legacy AGP slot. Well, as it turns out, I was wrong abut the slot being 3.3V legacy. I just checked the online manual today and it turns out that my Dell from 2000 has a 2X/4X AGP 2.0 slot (which is 1.5V I believe)...given this new development, does that mean I can fit all the newer AGP cards in my Dell for HTPC use, such as an ATi All-in-Wonder? Will my AGP 2.0 slot work with newer AGP 3.0 cards, such as most of the 4X/8X cards on Newegg?

The mobo chipset is Intel i815. Will that accept newer AGP 4X/8X cards?

I still don't understand why the AGP connector isn't keyed for AGP 2X/4X. Why is that?

Here's a pic of the AGP connector itself, notice lack of key:
http://i78.photobucket.com/albums/j120/996gt2/DSC02147.jpg

Here's a pic of the AGP connector on the TNT2 currently in there:
http://i78.photobucket.com/albums/j120/996gt2/DSC02145.jpg

 

[996GT2]

midday bump

 

[996GT2]

bump

 

[Peter]

An AGP 2x/4x connector does not have a key tab exactly because it supports BOTH signalling voltages - 3.3V for 1x/2x modes, and 1.5V for 4x/8x.

You'll find that AGP 1x/2x slots (3.3V-only) are keyed one way, and 4x/8x slots are keyed the other way.

Cards in turn either have one key notch if they support only one signal voltage, or two if they can handle either.

 

[996GT2]

so basically my connector can handle newer AGP cards like Radeon X series AIW?

 

[Peter]

Yes. It'll run them in 4x mode, but since 8x cards MUST be backward compatible to 4x operation, that won't be a problem.

Keep an eye on power supply strength though.

 

[996GT2]

Yes, it's got a rather weak 200W PSU, but I am probably going to swap out the 250W one from a Dimension 4550 later on. And I'm not going to be putting any hardcore hardware inside this machine...probably just an X700 AIW or something of that sort.