PhysX causing low GPU usage (GPU PhysX)

1) I don't know how you monitor GPU "usage" but what you want to observe is if the GPU frequency is dropping which indicates either:
a) thermal throttling, or
b) CPU bottleneck

**WTF????

I just tested and got the EXACT same FPS using HIGH vs MEDIUM PHysX (that was NOT the case when I bought it). I have VSYNC off. I can tell you my GPU isn't throttling based on my card fan speed. It's running higher than normal.

I'm going to RETEST in case I have to restart the program, so I'll update if I find out anything.

Other:
With my GTX680 + i7-3770K, I got 128FPS average at 1920x1080 mostly maxed (motion blur is off, possibly a couple other settings dropped).

The benchmarks is almost exactly TWICE what I get in-game because i carefully tweaked to achieve 60FPS most of the time in-game. I really, really hate benchmarks that don't indicate in-game performance. I think it's SHAMEFUL because the only reason i can think is to mislead people into buying the game who have weaker systems.

Running Batman on a rooftop is not the same as fighting a whole bunch of enemies in a different location.

I know how the benchmark works, and it's a running average. It does not reset for each scene. Just look at the min/max/avg and it carries over from the roof to inside the prison.

I drop from 90FPS at the start and slowly drop to 66FPS (1080p, I think max everything except no motion blur as I think there was a problem with that).

*I had to RESTART the game or else the benchmark used the same MEDIUM PhysX settings. So now i get this for my GTX680 + i7-3770K->

1080p, almost max, PhysX HIGH:
66FPS avg

1080p, almost max, PhysX MEDIUM:
128FPS

In-Game (PhysX MEDIUM):
*I don't know what to call the average as it varies too much. It's rough 40FPS to 125FPS. In some areas I'll start fighting at 90FPS and never drop below 60FPS, and in other areas I drop down to 40FPS (probably a bit below what's reported in reality).

Anywhere that PHYSX isn't used at all I'm sure to get the same performance regardless of PhysX setting, but according to the benchmark I'll see a huge drop when HIGH PhysX feature are used.

For me the game stutters a lot if VSYNC is OFF, or if I have it on but drop below the refresh (below 60FPS for 60Hz monitor).

So...
Long story short the benchmark would suggest I'd get 66FPS using PhysX HIGH, and in reality there would be times I'd drop to around 20FPS likely.

So like most games with benchmarks I run the benchmark, tweak thinking it may work, then play the game, get stutters, low FPS and have to tweak things.

Unfortunately, many people aren't comfortable with that and just suffer through stuttering. (theoretically a console is the way to go as the company tweaks for you, but many games drop under 20FPS at times with 30FPS max so that's not an option either).

Just FYI, but Adaptive VSYNC works great for several of my games. Not sure if it's helping Batman AO though. I think something in how the program is setup is preventing that working properly.

For Assassin's Creed Brotherhood for example, I tweak to maintain 60FPS about 90% of the time, maybe higher. I then force on Adaptive VSYNC and it toggles VSYNC ON or OFF (the main point is to avoid stuttering if you can't output fast enough to synch with the monitor because then your frame time doubles causing mixed frame times.).

Mixed frame times are also why games don't appear smooth sometimes. Hence the frame time analysis to replace frame RATE (FPS). You might have 60FPS reported and have an experience closer to 30FPS. Go run a game like Half Life 1 and it can appear incredibly smooth at 60FPS VSYNC ON.