I just got Oblivion, and one of the listed tweaks to make it run better is
to change the Max frames to render ahead (or Prerender limit in Riva Tuner)
from the default of 3 to 1 or 0.

So I tried it. And it indeed appears to give the FPS a pretty sizeable
boost, from about 30 FPS to around 40-45ish. And trying the Sims 2, I also
seemingly got a pretty big boost.

Are there any downsides to this setting? I can't really seem to find any
concrete information on just what this setting does. And most of that seems
to indicate the opposite, that it's meant to improve FPS by setting it
higher, because the card will render ahead on its downtime.