Lol, dedicated PhysX cards are still a thing? The 970 should be A-OK for handling PhysX on it's own, that really hasn't been an issue since the GTS200/GTX400 series cards. If you have enough processor overhead, you can also set the processor to calculate graphics as well through the Nvidia Control Panel. In addition, you can set physics to be calculated only on the GPU, or switch automatically between the GPU and CPU, depending on the current demands.