OCing Memory: Will It Improve Pr?

Great results.  If you get time I would try backing off slightly on the RAM speed  to see if you get the Disk I/O speed goes back to normal.  You may be handing data from the memory faster that the PCIe bus can handle it.  Remember Microsoft Windows and Premiere basic software were designed in the hard disk drive era an there may be some mismatches

But I am disappointed that the RAM overclocking on the CPU intensive score only changed from 163 seconds to 160 seconds.  For your i7-7900X 10-core at 4.7GHz at 160 seconds you are very close to the Threadripper 1950X 16-core at stock turbo speed of 4.0GHz which scored 156 seconds.  Of course you will probably outperform almost any other system on any non or lousy multithreaded coding because of the 4.7 GHz clocking.

With your 7 seconds for the very heavy GPU Accelerated timeline export it is the best score I have seen, of course for two Titan X Pascal's you should be the leader but is it worth it for Premiere Pro?  Those two are a $3000+ expense and I have two GTX 1060 SC & OC at $270 each that do it in 11 seconds.  I imagine if I added one more it would be within a second or two of that 7 seconds.  Running the same timeline with no acceleration (160 seconds) and with GPU Acceleration 7 seconds versus 11 seconds is almost insignificant.

The second PPBM number is the GPU accelerated 7-layer H.264 timeline is also CPU sensitive and you can see the improvement from 38 seconds to 34 seconds is clearly from the faster RAM.