The iMac Pro was only strong at multi-threaded tasks; its single-threaded performance was rather mediocre compared to recent Intel Macs.
| Single-Core | Multi-Core |
14-inch M1 Max (8+2 cores) | 1644 | 11715 |
8-core iMac Pro | 1065 | 7979 |
10-core iMac Pro | 1113 | 9378 |
14-core iMac Pro | 1091 | 11028 |
18-core iMac Pro | 1090 | 13408 |
8-core 2020 Intel iMac | 1252 | 8131 |
So, if you take the absolute highest end of the iMac Pro and have a heavily multithreaded task, you might still be ~14% faster than the highest-end MacBook Pro. But also much slower at single-threaded tasks.