Easy one would be the P part is single socket only.

I was browsing one day looking for barebones to throw in one of our clusters and saw Newegg was selling these 1U servers cheap ($2200-2300)

Usually with AMD desktop and server CPUs buying high core counts at lower TDP yields a great perf/ W figure

Actually the 7713 too (non-P, dual socket compatible) can be found for less than the 7C13, around $1500-1800:

https://www.newegg.com/p/2HE-001Y-000A5

https://www.ebay.com/itm/185284314106

https://www.ebay.com/itm/204640460566

Edit: from comparing https://www.servethehome.com/wp-content/uploads/2024/03/AMD-... and https://www.amd.com/en/products/cpu/amd-epyc-7713 it seems the only difference is the 7C13 has a Configurable TDP (cTDP, hence the "C" in product name) that is lower: 165-225W (7C13) vs 225-240W (7713). This would explain why the 7C13 is a tad more expensive than the 7713.

Hey Patrick, thanks for your reply and for all your cool articles, love STH.

I've found the same thing even with old Xeon e-series v2, high core counts with low frequency parallelize fantastically. Cheers.