Setting terrain textures to low, preload radius to 50%, resolution to 1080 and well, turning down a lot of other stuff as well...THAT made Syria work for me, without any single stutter.
i7-7700K CPU @ 4.20GHz (4 cores, 8 logical processors)
NVIDIA GeForce GTX 1080 Ti
32GB RAM
Samsung 1TB SSD for OS
Samsung 500GB SSD for recording
Samsung 4TB SSD for sims