With a 6970, you should be able to take the internal resolution very high. If you've put the antialiasing too high then you won't be able to though. Remember that 4x antialiasing is about the same as 2x internal resolution, 9x is about 3x internal resolution, and 16x is about the same as 4x internal resolution. If you put the antialiasing high without the internal resolution the same as your monitor's then you'll take a performance hit without seeing the benefit.
OS: Windows 10 64 bit Professional
CPU: AMD Ryzen 5900X
RAM: 16GB
GPU: Radeon Vega 56
CPU: AMD Ryzen 5900X
RAM: 16GB
GPU: Radeon Vega 56
