How to find my PC bottleneck for gaming

Specs?

Passmark will take your stats and compare them to other computers. They rank the parts too.

bavman,

Please see my specs below and tell me what is my bottleneck here:

CPU: Intel Core 2 Quad Q6600 (Not OC)
RAM: Mushkin 4GB (2*2GB) 1333 DDR3 on dual
Motherboard: Asus (sorry forgot its specifications but its with dual PCIe 2.0 16X, 4 slots RAM, Core 2 Due and Quad (No i7))
GPU: ATI Radeon Sapphire HD5970 2GB GDDR5 (single not OC)
OS: Windows 7 64 bit service pack 1
HDD: @7200 RPM (sorry dont know the other specs)

I always play at 1080p and try to get the setting maxed.

Information for upgrade:
Powers Supply Cooler Master 1100 watts
Chassis: Cooler Master HAF 932

While playing borderlands 2 I noticed that the physics has made my PC slows down, which is due to the design of the game that focused on using the CPU, and my CPU is really slow with physix. However, after setting the physix to low I still have a drop in Frame rate when I reach the end of a map and look back at the map, the drop get to almost 25. I tried to set the resolution and all setting to low and still finds the drop in frame rate, is this because of Borderlands design or do I have a bottleneck somewhere I dont know about.

I remember in crysis, I had issues with 1080p and full settings, so I lowered the settings, Skyrim had the same issue but with the skyrim latest update on steam I was back to full settings.

So could the frame rate issue be from games and not from my system as evidenced by Skyrim post update and Borderlands 2 low setting test?

please help.