OLXb5 functions the same on 10 fps or 10000 fps (supposedly) the only difference is responsiveness in controls. Plus high fps with 0.56 means your client will flood out updates to the server (or am I imagining things?)
I've heard it does, so I did a little research.
I played around abit with the affinities and priorities on my cpu getting the fps to fluctuate between around 70 and 700 (I couldn't somehow get it to utilize 100% of one core) while playing on SorZ' sever. I kept track of how much of my network it utilized and it rose when the fps rose. Not too accurate but it does atleast prove that o.56b transmit more information the higher the fps is.
Speaking of differences in the physics. The most noticeable one is air control, you can't "walk" in the air at all when the fps approaches 1000 and your horizontal velocity drops to zero the moment you tries to airwalk in the opposite direction. Collisions are also much more sensitive, you'll stick to the ground and wall if you bumb into them, sometimes resulting in getting stuck on wall or the floor (can't jump from the floor or walk away from the wall).
OLXb5 does function the same whatever ones fps is. But only on the same cpu, e.g. collisions and controlls are much more sensitive with my new cpu(not entirely sure if it's only cpu-bound, but the cpu does play the biggest part) than with my old (Q6600@ 3Ghz vs AMD Athlon 3000+@stock frequency). On the other hand, the Physics does function as they did on my old cpu.