Discussing this in the other thread. Cubase 10 new build - I7 or I9? - Steinberg Lounge - Steinberg Forums
In most cases the 8700k will outperform the 9700k but…
If you need to turn off HT, expect to see the opposite true.
If you want super tight latency or use power hungry plugins, expect to see them even out.
The 9700k will all core OC easier and higher, which amplifies the 2 points above.