I recently found a "Viper V330 NLX" AGP with a Riva 128ZX chip on it. I was under the mistaken impression that the ZX was faster, but apparently this chip was only created to allow for 8MB of memory and a faster RAMDAC for higher resolutions.

Problem is, this card is only 4MB and there doesn't really seem to be any mention of it being a ZX anywhere. Everest shows the card as actually having the same RAMDAC speed and actually even a LOWER clock speed (95Mhz) compared to other Riva128 cards. The card looks like it is missing a capacitor (didn't notice until after testing) and wouldn't accept any drivers so I'm going to repair it and then see if anything changes. I'm still a bit confused by this.

Are the 128 and 128ZX totally interchangeable? To the point that later cards that weren't a "ZX" model might end up with a ZX chip without actually having any of the ZX features?

My card is an "E" revision and looks identical to this one, except that the main chip is a ZX like this one.