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PhysX and AMD in UE4

Hey all, I just ran the Elemental demo and it left me with some questions, and I apologize if I may sound like an idiot asking this, but I’m just intrigued.

The Elemental demo is absolutely full of GPU particles, with sparks flying around and slabs of stone being shattered. All of this ran perfectly fine (40-60 FPS average) on my system that runs a dinky R9 270X. I thought it may just be running on my CPU, but a CPU can’t possibly run all these physics effects at such a great speed. Afterall, Mirror’s Edge and Borderlands almost crashed my PC trying to simulate the tiniest of PhysX particle effects.

So my question is, has Epic Games figured out how to run PhysX, or some form of it, on AMD systems?

The GPU particles use Epic’s own implementation, rather than PhysX.

FWIW, PhysX does not run using *any *GPU features in UE4.

The thing is a few of the UE4 trailers released a while ago always emphasized PhysX, so that’s why I’m a little confused here

So even APEX should run fine with AMD graphics?

Yes, as far as I am aware.

GPU Apex/PhysX

It looks although GPU Apex/PhysX can be enabled somehow if you look into the directory
Engine\Binaries\ThirdParty\PhysX you see two folders containing multiple dll files. one folder named apex 1.3 and another named physx 3.3 they match perfectly.
I honestly don’t think Epic games did in-house particles cloth and rigid bodies, However even though the demo does indeed use apex physx rigid bodies,cloth and particles it looks like the cpu is leveraged for now as the solver for physx 3xx and up are extremely optimized for cpu and especially gpu.