Does Oblivion implement backface culling?
It wouldn't surprise me if the answer is "No.". The game runs so damn slow compared to every other game I own (at least one of which is more demanding, apparently).
I put it in wireframe mode and wasn't particularly surprised to see this:
(Sorry about the image loading times - slow server)
I'm not sure whether or not this means it doesn't use backface culling (it's probably just drawing every line in the map for the purpose of wireframe mode) but I only gain ~8 FPS by turning switching back to textured mode.
EDIT: Oh and I get no more than 20 FPS with it off, even if I turn all the settings (an I mean all) down to their lowest. I could turn the resolution down but then I'd be eye-raped by jaggies (AA doesn't work with HDR).
Sure, I could turn off HDR, but who does that? Oblivion is one of the few games out there that makes good use of it (I.E. It doesn't blind you).
In that particular scene I get 16 FPS in textured mode.