For reference, I have no issue staying almost capped at 60 fps with a Vega 64 & i7 6800k & 16GB ram & SSD, with following settings (in order as they appear on menu): 2tx, UH, H, UH, H, H, H, M, M, UH, H, H, UH, 20, 20, 10, at 1800p. Even in Rattay, the lowest spot is only a drop to 40ish fps (in as you come from castle, at the market centre), but maintains 50ish fps otherwise. H= High, UH = Ultra High etc 20 means maxed out slider, 10 half and so on
I also run the following modifiers in user.cfg:
cl_fov 80
r_TexturesStreamPoolSize = 8192
sys_budget_videomem = 8192
r_TexturesStreamingMaxRequestedMB = 2800
r_texturesstreamingDeferred = 1
r_TexturesStreamingResidencyEnabled = 1
r_TexturesStreamingMipBias = -3
r_TexturesStreamingResidencyThrottle = 0.8
r_TexturesStreamingResidencyTime = 120
sys_budget_sysmem = 15000
sys_streaming_in_blocks = 1
sys_streaming_requests_grouping_time_period = 1
e_PreloadMaterials = 1
sys_PakStreamCache = 1
sys_preload = 1
r_ssdo=1
r_ssdoAmountAmbient=1.4
r_ssdoAmountDirect=2
r_ssdoAmountReflection=4
r_ssdoHalfRes=2
r_ssdoRadius=0.04
r_ssdoRadiusMin=0.07
r_ssdoRadiusMax=0.1
e_svoTI_SSAOAmount=1.545
e_svoTI_SpecularAmplifier=0.82
e_svoTI_TemporalFilteringBase=1
e_svoTI_MinReflectance=0.19
e_svoTI_DiffuseAmplifier=1.12