1080ti Release Date - Gadget Planet

I'm still using old 1080Ti GPU. I'm connecting them with DP1.4 with freesync on. Everytime I set refresh rate 4K 120Hz, color drops to 8 bit, 422, limited.

In order to get 10 bit full, I have to set 4K 60Hz. I updated monitor to latest firmware. Is this the issue caused my old GPU? Is it time to upgrade my GPU to 3000 series and use HDMI2.1?

1080ti release date,