An EPYC 7K62 does 33.5KH/S. it takes 270w total system power at the wall.
So I just bought one for $360 off eBay. The motherboard was expensive, $500 and the ram was $300 but I did go way overboard and got 256gb (AI tasks)
But my thinking was $599 for a 9950x or $450 maybe for a used 7950x? Not sure how much you are getting your 5900x for, but the cost is immense per KH I think.
So $1200 for 33.5kh @ 270w or $450 cpu, $300 board, $100 ram so $850 for 15kh @ 120w (presumably at the wall? Because my software vs at the wall are WAAAY different)
I haven’t even bothered playing with XMP on or off or anything of that sort. So my stock efficiency matches your painstaking tweaking. But I can buy 100kh for what you can buy 67.5kh for. Make any sense?
So I guess the 5900x in particular is a little cheaper: around $240 so then it’s $1200 vs $600 give or take. Per system.
So 2 of 5900x 's would generate 30kh where mine generates 33.5kh
Not a huge difference. But in the back of my mind I figured there might be some.