Wow thanks a lot guys! So many responses on such a short time, this place is really awesome.
Since I don't play very often on my machine, I really want to prepare it for the upcoming Red Dead Redemption II and plan to start on VR early next year. For now I mainly use it for video editing, 3d modeling an a bit of gaming (GTA V, CS-GO, Just Cause 4).
So I think the CPU is OK then, just a little OC and it should be fine since I have an Intel water cooling system for it. I was mainly worried about the slow RAM and old motherboard.
I forgot to say: I use it on a LG 55SM8600 4K TV for playing games...
Do you think the current motherboard should be fine? No need for a faster PCI connection or anything else?
Thanks again!