4 cores not enough for Synapse 3?

If i play cpu heavy games, my Huntsman TE has a problem with sticky keys. No Problem at all if i close Synapse. I had the same Problem with the Huntsman Elite before so i think, the reason is not a damaged keyboard.
Could it be possible that Synapse need a specific amount of CPU-Power to work right? I have a 6600k. In games like CSGO the CPU is fully occupied.
I already made a clean windows reinstallation since the Problem persist.

Somebody has the same Problem?