Older Quad-CPU servers seem to be a "goldmine" right now with GPU shortage and popularity of Cryptonight coins like ITNS.
Even so, older CPU's aren't particularly efficient with cryptonight.
I have an old Intel Xeon E5645 6 core (85W TDP) in my secondary machine and it struggles with 200 H/s with 6 threads. And it should excel with its 12 Mb of cache.
My laptop has a tiny core i7 7500u (15W TDP) and it does 130 H/s with 2 threads...
I also run a ton of older Xeons... they do plenty well for being cheap as they are (get your money back in a month). I mainly use X5660 models on 5 threads... about 230 H/S
Of course more modern CPUs are more efficient but they are pricey.