I doubt I can make Epyc look bad
But if I had to try to pose a challenge...
(dislaimer: I am not trying to promote our projects as most of you are not target groups, but I feel real-life examples can add value and some clicks and "animation" to discussions like this)
We run a SaaS service similar to a hybrid of Shopify & Etsy. PHP, mySQL... on a private cloud.
Its major part is invocing, real time VAT register, stock status (in-store and webshop concurrently that also have flash sales options)...
We cache what we can, but many things we can not. At least not without the expense of a much bigger app complexity.
On top of our main service we also develop & host very customized webshops i.e. personalized books for kids
https://dreambookstudio.com (like LostMyName) or
https://fortnitecover.com - personalized designs for T-Shirt, notebooks etc. where even PDF/JPG's are "just created" and do not even get a chance to get into ARC/L2ARC and Cloudflare CDN as they are often obtained only 1-2 times.
Puppeteer (Chrome headless) is also very important for us and since it runs on Node-JS single core perf. and RAM are very appreciated. Therefor we will probably test Ryzen 3900x before Epyc for that process/node.
So far:
We went for Intel Optane for DB as our DB is still small enough.
Optane also for SLOG & L2ARC also for our CDN (Proxmox ZoL).
We probably will not hesitate to put our next NAS/CDN on Epyc based on STH reviews and comments like
Will AMD Epyc 7351P & Supermicro H11SSL-i do FreeNAS 11?
I assume Epyc would be better than our current setups E5-2690 & E5-2640 v1's and E5-1650v4, but we try to see what is on the market or is coming up, buy couple of pieces that we believe would work for us well and set them up. We do not chase those last 1-10% performance leaders/tweaks/overclocks..., but since AMD has had quite some issues with memory latency with Zen that number stuck out for me.
Is this one of those cases where "Well, you will probably not see significant improvements with Epyc aside from lower power-bill" ?
But I agree that in general Epyc looks like a future proof choice and a very good one regardless what you do. We run couple of tests on our own, but most of time rely on (exceptional) know-how of people like
@Patrick , Allyn Malventano, Wendell, some redditers... (LTT not so much anymore, but I liked Patrick's visit there