Please thank Newtekie1 here: The Dedicated PhysX card FAQ - Read this before a... as he put half of this FAQ together. In the past few weeks I've seen a lot of topics popping up asking the same questions about dedicated PhysX cards, so I figured I'd try to answer some of the most common ones here. What dedicated PhysX card should I get? Probably the most popular question about PhysX cards seen here. If your main graphics card is an nVidia card, the simple answer is you don't need a dedicated PhysX card, and shouldn't buy one. Here is why. With the GTX400 series cards, they are already powerful enough to handle the PhysX calculations by themselves. They do not take a performance hit from the PhysX calculations. That isn't to say they won't have lower FPS when PhysX is enabled, but the lower FPS is caused by the extra graphical rendering power needed to render all the extra particles and fragments added to the scene by PhysX, not the PhysX calculations themselves. Now, if you are using something lower than a GTX460 a dedicated PhysX card might help take some load off the main GPU. However, the money would be better spent on a second GPU for SLi than on a dedicated PhysX card. If your main graphics card is an ATi card, then something very weak will be good enough. Generally anything with 64+ shaders will do the job just fine. The GT240 seems to be a very popular card, as is the GT430. You don't need anything more powerful than that. PhysX actually takes next to no GPU power to do the calculations. Will a dedicated PhysX card boost performance in every game? Absolutely not! It is a common misconception that because essentially every game uses some kind of physics engine, that a dedicated PhysX card will boost performance in every game. It is important to not confuse physics in general with PhysX. PhysX is just another physics engine that is only used in certain games. And while the list of games that use PhysX is somewhat large, the list of games that use hardware accelerated PhysX is rather small, something like 15 games. So only 15 games actually use the graphics card for PhysX to begin with, and of those 15 only something like 5 or 6 are real well known blockbuster games. Can I play a PhysX game without an nVidia graphics card? Of course! However, you will not get the high end PhysX effects, which essentially amounts to nothing more than eye-candy anyway. I've played every one of the big PhysX titles, and I can say they are just as enjoyable without the PhysX eye-candy as with. You will also still have physic in the game. The reasons is PhysX offers a software option that isn't as detailed as the hardware accelerated options, and this option is actually what is used in most of the PhysX games on the market. This is why the list of games that use PhysX is 40-50 games long, but the list of games that use hardware PhysX is only 15 games long. Software PhysX is pretty on par in terms of capability with the other software physic engines available today, such as Havok. And it is also available to everyone, with no need for an nVidia graphics card in the system. This is why it is more appealing to game developers than the hardware accelerated PhysX. This software PhysX option should not be confused with option to run the hardware accelerated PhsyX on the CPU. Those are two totally different things. The software option to PhysX runs the calculations on the CPU, but it also tones down the amount of calculations done dramatically, with a lowered visual effect obviously. Running hardware accelerted PhysX on the CPU does not tone down the amount of calculations, and hence performs extremely poorly when run on the CPU, making the game pretty much unplayable. Can you run a dedicated nVidia GPU along side a primary ATi graphics card? Yes. Although not officially supported, there is a simple to apply hack that allows this. You can read how to do it here: Things you need For Installation: -ATi/AMD drivers: www.amd.com -Nvidia drivers (use 258.96's): www.nvidia.com -1.04ff PhysX mod: http://www.ngohq.com/graphic-cards/17706-hybrid-physx-mod-v1-03-v1-04ff.html <--Not needed if Nvidia card is the main video card output For Testing -GPU-Z: http://www.techpowerup.com/gpuz/ -FluidMark: http://www.ozone3d.net/benchmarks/physx-fluidmark/ (Latest version does not work, try an older version) -3dMark Vantage: http://www.futuremark.com/benchmarks/3dmarkvantage/download/ -A video card for video output (ATi or Nvidia) -A PhysX supported video card for PhysX. This can be the 8 series (G92) and up. Installation Install ATi/AMD/Nvidia (main video) card and drivers. -Already done this? Good! Move on to the next step. Install Nvidia (PhysX) card and drivers -Install Nvidia card into empty PCI-E slot -Turn on the computer -Install Nvidia drivers. When the installer asks you to restart, open and apply the 1.04ff PhysX patch, then restart. <-- Not needed if Nvidia card is the main video output Making sure it works Upon restart, PhysX should be enabled. There is no place to go to enable or disable PhysX other than uninstalling the 1.04ff Patch. GPU-Z should tell you that PhysX is enabled. Try using Fluidmark to see if it performs/works like it should with a PhysX card. Of course, now is a good time to actually use your PhysX card and enjoy it. Games like Mafia 2, Batman: Arkham Asylum, Unreal Tournament 3, Mirror's Edge and others are good places to start. *This has not been tested with the latest Nvidia WHQL drivers (will be soon) *It is possible that some of Nvidia's newer GPU's such as the GT430 (GF108) will not work yet. (GF100/104 work.) *Please post your benchmarks, suggestions, etc. using your dedicated PhysX card. We can then see what some good combinations are and how much of a PhysX card we really need. I will be soon testing a GT240 vs. a GTX460 in different games and benchmarks. *Please post your benchmarks, suggestions, etc. using your dedicated PhysX card. We can then see what some good combinations are and how much of a PhysX card we really need. I will be soon testing a GT240 vs. a GTX460 in different games and benchmarks. Please feel free to add any comments or suggestions to make this guide better. Thanks!