Modders defy PhysX lock-out

Nvidia really doesn’t like gamers using ATI cards for graphics, with a second Nvidia card for PhysX.

In fact, its drivers automatically disable GPU-accelerated PhysX if an ATI card is present. Never fear, though, as the driver modding community has just issued an updated mod to enable Nvidia and ATI GPUs to cooperate in PhysX-accelerating harmony.

The driver tweakers over at NGOHQ have just issued version 1.03 of their Hybrid PhysX Mod. It’s a neat little tool that enables you to fool Nvidia’s driver into enabling PhysX on an Nvidia GPU, even if you’re using an ATI card as your primary display device.

Given that Fermi cards are still proving difficult to get hold of, this is currently one of the easiest ways of getting both DirectX 11 graphics and GPU-accelerated PhysX from the same machine.

The very first version of the Hybrid PhysX Mod was released back in October 2009, but NGOHQ has added a few tweaks since then. The latest version works with Nvidia’s 197.45 GeForce driver that was released earlier this month, for example, as well as the 9.10.0222 PhysX driver from February this year.

Version 196.75 of Nvidia’s driver apparently introduced some issues with the mod in reversed gravity situations, as well as a general slowdown after a few seconds of PhysX processing; a problem that some suggest was created deliberately. Either way, this is now fixed in version 1.03, which also includes improved patching logic, so that the mod doesn’t attempt to patch non-existent files any more. The mod will also now try to patch PhysX system software files.

You need to perform a bit of jiggery pokery in order to get the mod running, including setting up a fake second display for the Nvidia GPU, but you can find the full instructions at the download page linked above. According to NGOHQ, the mod should also work with CrossFire configurations, with the Nvidia card in a third PCI-E slot, as long as you have enough power going to all three graphics cards.

You shouldn’t need to worry too much about PCI-E bandwidth for PhysX either, as it’s nowhere near as demanding as 3D graphics work. PhysX Info reckons that you can get away with just four PCI-E lanes to get the most out of GPU-accelerated PhysX, and that the bandwidth from a single lane would probably suffice, too.

If you bought a Radeon HD 5000-series GPU, but still have your old GeForce 8800 GTS card sitting on a shelf, then why not put the latter back in your machine and have a play with GPU-accelerated PhysX?

If you fancy trying it out then, you can grab the Hybrid PhysX Mod packaged in a 2.19MB RAR file from here.