AMD Ryzen Threadripper 3990X 's Advantages
Larger memory bandwidth (95.37GB/s vs 47.68GB/s)
Larger L3 cache size (128MB vs 32MB)
AMD Ryzen 7 3800XT 's Advantages
Released 6 months late
Higher base frequency (3.9GHz vs 2.9GHz)
Lower TDP (105W vs 280W)