I was wondering when the terrible devs would put their ban hammer down on people telling the truth.
This was in response to a lot of posts from AMD users, very angry ones that went in full curse mode, they are wondering why their R290X or R295X2 run like a dog in this game.
I linked a FULL verbatim quote directly from Ian Bell, their lead developer, where he SPECIFICALLY raises the problem, identified as PhysX hammering the CPU on AMD setups.
There's no lies there when it comes from the man himself responsible for making the game.
On a side note, the devs have deleted several other complaints regarding poor AMD performance.
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I think it may be a simple case of CPU PhysX on CPU = single core only, like in the old days IIRC. So if its bottle-necking 1 core, it will slow down the game. The question is why on NV GPUs, is there no effect. Maybe their DX11 MT driver is able to alleviate the GPU when 1 CPU core is hammered but AMD's can't, or that the devs put the render thread and the physics thread on the same thread. But definitely PhysX is the cause of the problem for AMD GPUs.