i heard that we need to have and upgrade nvidia card or plugin or driver or something else to run physx? is it?
but why unity doesn't seems to have upgrade,install or run somthing based physx support in it? i really don't understand!! coz i have no nvidia driver or card but, i can run physx in unity normally!!
You only need a PhysX card in order to run hardware accelerated physics. The engine itself is just code (like Unity), so it will run regardless of hardware, at least as far as I'm aware.
If you heard anything, it wasn't about Unity. There is no support for hardware physics acceleration even if you had the hardware to use it.