I've never used either of these computers, but maxing the specs on a System 76 Thelio Massive gets you:

- 2x Xeon Platinum 8280 (28 Cores each, 2.7 - 4.0 GHz)

- 2x 768 GB ECC DDR4 Memory (6x128GB per CPU, 1.5TB total)

- 1x 2TB NVME drive

- 1x 28TB SSD

- 4x Nvidia GeForce RTX 2080 Ti (11 GB, 4352 CUDA Cores each)

- $ 53,356

I've never used either or anything remotely close to either that or the mac pro, so I could be missing something, but the system76 seems like much better value than the fully maxed Mac Pro at $ 53,899