I don’t see why Unreal would be “incompatible” with your hardware. In my case, this CPU is at least 3x faster than the old Core i7-4770. Even faster with shaders.
It looks like a hardware problem.
I’m not an expert here, but I can think of a few things to check.
Are drives connected to SATA3 or slower interface? It’s a common issue. Although I doubt any Threadripper motherboard has slower interfaces, these mobos are so expensive. What mobo you got anyway?
What’s CPU temperature under heavy load? I got 55 C at 100% utilization (72 C if you’d look at TControl temperature).
RAM… I’d recommend at least 32 GB quad channel memory. CPU will use it well, the fastest DIMMs you can get. You need a lot of memory to feed all 32 threads.
Of course, even 16 GB should be at least as fast as an old machine, right?
When I installed 3200 MHz memory, I had to change the profile in BIOS to actually get that speed. IIRC it was just 2133 MHz by default. Perhaps anything something else to set in BIOS…
You want to read this article. I found it quite helpful while I was assembling my own rig.