Significant FPS drop (~15 FPS) with TDS GTN 750 in AirfoilLabs King Air 350 (XP12)

[sViterbi]

Hi all,

I’m running X-Plane 12 on Windows and recently purchased the AirfoilLabs King Air 350 and the TDS GTN 750, where I notice a consistent and quite significant performance hit.

Issue:
When I turn on the TDS GTN 750, I experience an FPS drop of around 15 FPS (raw, not frame-gen). The drop is immediate and consistent.

Details:

Aircraft: Airfoillabs King Air 350

Add-on: TDS GTN 750

OS: Windows

Simulator: X-Plane 12

FPS impact: ~ -15 FPS when GTN is in use

Observations:

FPS is stable and acceptable without the GTN 750

As soon as the GTN is turned on / displayed, FPS drops noticeably

The performance hit persists throughout the flight

No FPS drop observed with default avionics in the same aircraft

Question:
Is this expected behavior due to how the TDS GTN 750 is rendered (e.g., external process, CPU/GPU load), or could something be misconfigured on my side?

Any known tweaks or settings to reduce the performance impact?

Thanks in advance!