> > To use your 8800 Gt you'll need to build or buy an edid dongle.
> What good would that do, isn't EDID is for digital displays? Is it even possible to
> identify a 15Khz analog monitor via EDID, and would the video card know what to do
> with the signal just from EDID data? I doubt it.
> If it's really possible, please post details.
I'm not an expert but I'll try to explain (in the level that I understand)...
The most common way to use 15/25hz on relatively modern vga's is using soft15hz (there are some custom ati drivers that also work, but that's new to me and I never had any ati card). Most nvidia cards wont accept these low resolutions without your monitor giving proper edid information about supported resolutions (I don't know of any 15/25hz monitor that has edid). So the way to use most nvidia cards at 15/25hz is using soft15hz + an edid dongle, which you can buy or build yourself using instructions from BYOAC forums. I've build one to use with my 8800 gts g92, It worked very well (it was a pain in the ass to solder it since I can't see that well), but my card was already dying because of one leaking capacitor and it didn't last much longer...
Currently, the the best way to go 15hz is using 3xxx and 4xxx series ati cards with custom drivers. I may buy one, since my monitor is just collecting dust, but I'm currently broke and our economy (Brasil) isn't helping (strong dollar + 60% of interest (imports) for everything but books isn't a good combination).