It's a monthly fee for the pro version but it's about a 2 yr bnreak even with just buying it at $199
If you're unfamiliar with the history, Prepar3d is an evolution (by Lockheed Martin) of the old FSX codebase - but they've updated it with multi-core support, DX11, etc. Most (but not all) FSX addons are compatible, and it gives better frames at MUCH better visual quality than FSX.
Actually, I'd expect most new 3D engines to be prepared for heavy multithreading by now, but many new games at the moment are still based on older engines. 2015 and on, maybe not so much, when people start releasing things backed by UE4, CryENGINE (4), Source 2, FOX Engine, etc in earnest. I think the majority would target a quad-core, and might be surprised to find themselves running on a 6 or 8 core.
Seriously though, what are you talking about?
Even the puny Raspberry Pi (ARM v6 at 700Mhz!) is able to stream video in FullHD thanks to its dedicated GPU.
A slow CPU can still be a bottleneck if paired with an high-end GPU, but in general a cheap CPU with an expensive GPU is a much better set-up for gaming than the other way around.
(Of course there are exceptions, but this is generally true for your average AAA title).
The video encoder/decoder has a little fixed-function logic, but the VC4 is rather good at vector operations itself, particularly 2D 16x16 and 32x32 ones, and probably has at least as much general compute muscle as the ARM, I'd say? It is not easy to program efficiently, however, and its pipeline doesn't seem to like branches very much. And trying to do ChaCha20 on it is tricky because I can't seem to find a way to address the diagonals...
Edit: first Google hit to satisfy parent, since replying is disabled. Valve goes multicore [2006] http://techreport.com/review/11237/valve-source-engine-goes-...