Hi guys I wonder if any of you would happen to know how much of a conversion speed does a i7 8700k cpu with 16gb or ram would reach in conversion speed?

I happen to have i7 9700k which does not have hyperthreading so its 8 physical cores. Music is on external usb3 hdd and conversion destination is a 3.5 wd blue hdd. The highest I got was around x450 speed sometimes less.

Im wondering a lot if got better results if I went for i7 8700 with 6 cores and 6 ht cores making a total of 12 cores.

1st world problems, right?