Yes, I have a Threadripper 1950X - it absolutely eats Terragen renders!
One of the first things I did with the system just out of the box was try the Terragen benchmark test - it came third - with a fairly conservative overclock 3.8 (from base 3.4ghz)
I have 64gb 3000mhz RAM, but currently running at much less than the rated speed to keep the temps down - currently my O/C is:
3.8ghz CPU
2166 mhz RAM
and my render temperatures never get above 66 degrees (max temp for this CPU is 68 degrees)
I'm going to let this bed in for a while - after all, my Terragen renders are about 4-5 times faster than my old Intel Core i7 960 4 Core!
One regret is not getting better cooling - I have a single fan Corsair AIO Water Cooler, which does a decent job at the the current setup, but is at its limit I think. Later I'll invest in a better cooler and push the overclock and ram speeds further - will be like getting a bit of an upgrade.