i have an ati card at the moment and didn't need a driver at all. physx worked. i also don't have any games that use physx installed.

but i also find the reported driver problems worrying. so with a nvidia card you always need a driver? the driver isn't included with the graphics driver?

i hate installers. i don't want to deliver my projects with an installer. i think the whole physx driver requirement is very unprofessional and totally unnecessary. they should simply always use the cpu if no cuda hardware is available.

Maby someone can upload an A8 physics demo (a compiled exe).
So I can test that on different computers.

If it really requires a user with an older XP Machine to install the 33MB PhysX Driver, (http://www.nvidia.com/object/physx_system_software.html)
its not an option to use physics anymore for small projects.

Downloading and Installing such a big driver would be too much to demand for
running a small casual game using physics.

What about the Newton Game Dynamics wrapper for Gamestudio - could it be an alternative? AFAIK it also works with A8. Are there any drawbacks using it?

Gamestudio itself is a PhysX application, so you can test it on different computers. A compiled EXE alone will certainly not work when you do not add the driver.

PhysX accesses nVidia hardware and under Windows you always need a driver for accessing hardware. I dont think that the video driver that you install with your nVidia card will be enough.

There are lots of PhysX titles out, many new games use PhysX, its the main physics engine. Personally I dont see any problem with the driver, but this is mostly a matter of taste.

but why do you need a special physx driver? it should only require a cuda driver and the cuda driver should come with the graphics driver in my opinion. if there isn't a cuda driver then the physics engine automatically should use the cpu.

as far as i know the gpu still isn't used for gameplay physics anyway but only for eye candy stuff like particles and cloth.

it makes no technical sense. no other physics engine has such silly requirements.

physx is the main physics engine because they have loads of marketing money. not because it's better than others. they even have paid many aaa developers for using it.

AFAIK, nVidia is working on a CUDA driver for PhysX. There was a discussion about this on their developer forum.

Marketing money may have something to do with the PhysX leadership but IMHO the main reason is the hardware acceleration.

their hardware accelerator card was a total flop.

...and as far as i know currently the gpu only gets used to accelerate cloth and particles. you can't use gpu acceleration if gameplay depends on the physics since then you only could target your game to certain nvidia cards. physics also can behave differently on cpus and various gpus because of floating point precision issues and so on.

so i don't see the big advantage of hardware acceleration. it still will take a while until cuda and opencl are more mature and more suited for physics calculations and then all physics engines will also support gpus of course.

No, it does not use a hardware accelerator card. That was the predecessor Agaia. PhysX uses the GPU hardware for accelerating all physics functions, not only for cloth and particles.

I am also very sure that it does not behave different on different CPUs and GPUs. There would be no logic reason for that. Floating point is IEEE standardized.

I dont see a reason why PhysX does not have a small fallback dll,
that does the physics calculations in the CPU, when no
driver is installed.

By including this dll into the engine or into the install
folder, there is then no requirement to ship a small Tetris game
with a 33MB bis driver installer.

it can behave differently. physics engines are very sensible about floating point precision. most cpus internally use 80 bits and gpus only 32 bits.


tell me a game where you really notice the difference of hardware accelerated physics except for eye candy.


if gameplay depends on physics you can't really use hardware acceleration. if you have 10 times more physics objects in your levels on the gpu version then gameplay would have to be totally different for the cpu version. it would be a different game. that's one of the reasons why most games only use the additional power for eye candy (particles that don't affect anything,...).