*sighs*
Well, I've learned some depressing stuff:
a Dedicated PhysX Unit appears... shit.
I gained no FPS in Mirror's Edge, Metro 2033, or Batman Arkham Aslum. I'm very disapointed, because, in theory, this seemed like a no-brainer.
I guess you could say that a dedicated PhysX card, as an idea, is a misnomer? Either way, it sucks.
All I've achieved is a lot more heat, and a fair bit of extra power consumption. Thank God I didn't decide to buy a separate card.
There's not much point in showing you my findings, but here:
The following FPS is the average value, and the values were taken either from the game's benchmark feature or Fraps' benchmark feature within 30 seconds of the same scene, both with and without the 550Ti set as the dedicated PhysX card.
Batman - Arkham Asylum
----------------------
With DPC = 60
Without DPC = 60
Metro 2033
----------
With DPC = 73
Without DPC = 73
Mirror's Edge
-------------
With DPC = 91
Without DPC = 113
Mirror's Edge is a weird one: I was stood at the same spot with a lot of fancy PhysX fog on the screen, and it appeared to gradually grow over time, creating more and more fog, but the increase in fog because unapparent after the initial fog had filled up. The FPS started dropping 1 by 1 for quite a while, before completely clearing; whether this is a safety measure to ensure the FPS doesn't go too low, or whether it's a bug, I'm not sure.
In a nut-shell, PhysX should be left on the main card(s).
It's just a shame that I now have a pretty sweet 550Ti card that's gonna go to waste; guess I'll have to flog it. >.<