|Please read what I said about using a 2X capable card on more recent mboards - you can DAMAGE some mboards when you install the card!!|
"Okay, thanks for the info. Doesn't the fact that the video chip set on the MoBo sharing system memory mean that since there is 512 MB of RAM on that PC, I should essentially have a video chip set with the amount of RAM I have free?"
It doesn't work that way.
It doesn't use free ram -some of the ram is dedicated to be used with it.
Depending on how the mboard bios reports it, the amount of ram shared with the onboard video is often subtracted from the total mboard ram amount because it can't be used by the operating system or the user for data.
The amount of ram shared with the onboard video is either set to one setting and you can't change that, or it is set to a default setting and you can change that to a higher setting in the mboard's bios Setup. In any case it should never be set to more than 1/2 of the total ram installed on the mboard, and you usually can't set that anywhere near that anyway if you have a reasonable amount of ram installed.
" Then why is Halo reporting the chipset as 16 MB? "
If you mean the video ram amount, you may be able to increase the amount in the bios Setup settings, or not.
When you install a card in a slot, there's a 99% chance Halo is only going to be able to see and be able to use the ram on the card.
"I was Googleing and found a couple things about sharing system memory with AGP video cards"
99% of the time, that's not possible. because the mboard no longer shares the mboard ram when a video card is installed in a slot.
"Is there any case that this would be possible?
(I mean, sharing system memory with ANY video card)"
You certainly cannot share system memory with ANY, as in all, video cards (in slots) in any case, on any mboard, with any main chipset.
The only exceptions I know of are mboards with quite recent specific main chipsets, when used with PCI-E X16 video cards with certain specific video chipsets made by the same maker as the main chipset.
I know of no such thing for AGP cards.
E.g. AMD/ATI main chipsets call that a Hybrid feature - the card must have one of a few ATI video chipsets.
If the card doesn't have one of the specific video chipsets that can be used with the main chipset's Hybrid feature support, the onboard video is automatically disabled when you install a video card in a slot.
ATI has been using the RAGE name a long time.
The original RAGE 128bit series chipset cards came with 8, 16, or 32mb on the card, and were the first video cards with built in hardware DVD acceleration playback support. I have two - one of which is Rage Fury, the top model of the original 128bit series, made in Canada, TV out, 32mb was the only choice. The Rage Pro 128 bit series was the first ATI one that was 1X/2X/4X AGP - you can still get new cards with that chipset.