https://www.dell.com/community/en/c...-rx-570-bios-bricked/647f7f3ff4ccf8a8dedb7f71
From that Dell page.
PS 8300 / Vostro 460
I think this is a NON UEFI system.
If there is a newer UEFI bios then secure boot must be off with Legacy Option Roms ON. Otherwise you can ONLY use Radeon HD series
aka HD2400 HD3400 HD4600 HD5770 HD6670 HD7750 HD8000 series.
WILL NOT WORK with ANY R Series card due to the Video Bios not supporting DOS VESA Video mode 103.
I don't know if the GTX 1660ti is UEIF only and does not support in it's video BIOS running on old non UEIF systems.
I know the GTX 1060, 1070 and 1080's will work and that's where I stop on these old systems.