Game should utilise GPU as opposed to CPU

yahwho · Apr 29th 2018

Hey JIW!

They say a picture is worth a thousand words.

I really do appreciate that writing code is not easy! But the game does appear to utilise the CPU when it should utilise the GPU(s) available to it.

You will see from the following screen grabs that when running the game it uses (on my rig at least) 60% of the CPU time on all four cores.

In contrast, the GPU which should be the graphics power house, where there are 8 cores available, only one core is being used at about 35%

Feels a bit like going shopping to the local corner shop in a Bugatti Veyron. ( Honestly I really do wish I knew what that felt like! )

red51 · Apr 29th 2018

Well, the game requires a powerful CPU, since there are lots of computations going on - especially the world generation is quite demanding. Most of these things can't be done on the GPU. Certain things can be moved to the GPU, e.g. the player/npc animations, and that's actually planned (but this will not result in huge performance improvements). Apart from that, it's also possible to use OpenCL for computations, but since drivers (especially old drivers) of certain graphics card vendors have a pretty bad quality when it comes to OpenGL, I'm afraid these drivers probably also suffer from severe issues concerning OpenCL. Unfortunately lots of people are using outdated, broken drivers...
But this is anyway only suitable for certain things. Especially when it comes to the world generation, there needs to be a proper synchronisation between the CPU and GPU - some of the critical tasks can't be outsourced to the GPU.

But you also have to keep in mind that people with weaker graphics cards already experience around 100% GPU usage in some cases (depending on the graphics settings). And there are some features on the todo list which will have a noticeable impact on the rendering performance (i.e. the GPU), e.g. dynamic shadows, parallax mapping and tessellation. I'm afraid there isn't much room for optimizations if we also try to move too many computations (which were originally done by the CPU) to the GPU

yahwho · Apr 29th 2018

Thanks for the reply / explanation

The only 3D OpenGL stuff I ever did was a bouncing ball hehe - and I know that was tough to code

Lonelobo · Apr 30th 2018

Looks like it also depends on the cpu familly how mutch the game uses? I have a i7-5960x and the game seems to use 1 core almost to the max and a few other cores, and only 50% GPU (still low fps around 25fps??) So i guess there is still some optimalization possible on pc's with lots off cpu cores and high end GPU's?

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