Question What will fix my cpu bottleneck ?

[genar]

I just bought a rtx 2060 (1365 mhz) and paired it with my old Xeon W3550... the problem is... i cannot upgrade my motherboard and it only accepts following processors :

1. Xeon X5677 ( 4 cores, 3,47 ghz )
2. Xeon X5687 ( 4 cores, 3,6 ghz )
3. Xeon W3580 ( 4 cores, 3,33 ghz )
4. Xeon X5680 ( 6 cores, 3,33 ghz )
5. Xeon X5690 ( 6 cores, 3,47 ghz )
6. Xeon W3680 ( 6 cores, 3,33 ghz )
7. Xeon W3690 ( 6 cores, 3,47 ghz )

So the main question here is... which processor would you recommend to solve or to improve my cpu bottleneck ?
Im glad for all responses i get !

 

[NightHawkRMX]

Well, I would suspect thanks to the age of the chip, there might still be a CPU bottleneck at 1080p with any of these CPUs. Either of these CPUs should help to eliminate the bottleneck as they perform similarly. Go with whatever is cheaper.
Xeon W3690 ( 6 cores, 3,47 ghz )
Xeon X5690 ( 6 cores, 3,47 ghz )