First professional build

Hi,

I'm an electronic engineer, and I've only used notebooks until now, so this is a bit new to me. I am looking for a build that can handle smooth workflow and occasional gaming. I run software like MATLAB/Simulink, Altium Designer, and Comsol Multiphysics, so I’m leaning towards a 16-core CPU to better handle those simulations. I was considering something like the 9950x3d, but I'm open to any suggestions for better or more affordable options—even from Intel.

I haven't settled on a motherboard yet, it'll depend on the CPU choice, maybe a B650 for AM5?

For the GPU, I'm thinking of going with an older generation (for example a 3000 series) since my budget is around 1500–2000€ max. I mainly plan to play at 2K, so I don't need ultra settings, but I’d like to know if those older models still support modern games well.

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Also, I'm looking for a discrete case without glass panels or an overload of RGB—something optimized for air cooling (think Arctic Freezer or Peerless Assassin fans).

Any suggestions or recommendations on these components would be really appreciated. Keep in mind, the primary goal is smooth performance for work rather than gaming.

Thanks a lot!