I bought the game today and was fairly excited to play, after being absent from the first one for quite a while. But I am getting weird FPS drops for about 10 seconds. Wasn't able, to identify if something specific in the game causes it. FPS even drop, when setting up a new game / choosing a race. Just had HWMonitor running on my 2nd screen, which showed me, that every FPS drop corresponded with my CPU clocks dropping down to ~800 MHz.

To my system: 

PCPartPicker part list / Price breakdown by merchant

Here is my DxDiag file: DxDiag.txt

Trying to provide ppl with all informations I can find.

Edit: Found out, that tabbing in and out gets the clock back up to 4.5GHz. But it will drop again 5 to 10 minutes later.

Did you try to update Windows 10 ? Your graphic card driver could need an update, too.

And check out this:

Bad performances with a NVIDIA card

• Please verify if your monitor is plugged into the GPU and not the default slot of the motherboard.
• Go to the NVIDIA control panel.
• Then go to “Manage 3D Settings”, “Program Settings”.
• Look for or add “Endless Space 2” on the drop-list and tell NVIDIA to use the high-performance graphics processor instead of the on-board graphics card.

Source: Common fixes

I know. Updated it after posting. The issues are still persisting. 

Having to alt-tab after sometimes a single turn is kinda annoying. Although I enjoy playing another Endless Space title