For comparison, here's a slightly later Riva128 card also from STB. This one is marked Rev C, yours is Rev B. But I don't know if these are actually revisions of the same series of cards, so don't know if one is actually a successor to the other.
They're laid out totally differently, despite being close in age.
The memory chips on yours appear to be week 52 1997 and week 02 1998. Mine are week 08 1998, so that implies the card is maybe about 2 months newer.
Yours apparently supports some AV features and it's a bigger PCB (more expensive).
My Rev C is downsized, deletes the optional features and instead allows that L-shaped cutout some PCs wanted.
The Rev C doesn't have electrolytic caps at all, doesn't even have places to put them, instead it has a mix of surface mounted ceramics and tantalums.
No heatsink on my Rev C. I'm not the original owner though, so I don't know if there ever was one. When I saw yours I thought it must have been a mod - until I saw the posts above.
Both cards have the same BIOS version, but different dates on the stickers. The date on yours is wildly late - October 1998? Nowhere close to the other dates visible on the card. Somebody might have swapped that chip, or there was a weird time gap in it's construction.
