I just noticed something that I'm sure folks here will have quick ready answers for.

Desktops use i3, i5, i7, & even i9 in cases and have AMD as a direct competitor with increasing market share.

Servers seem to have Xeons, and AMD doesn't figure much.

I conclude the Xeon if better profiled for server use - but how?

How do you figure AMD doesn't figure much? The AMD Epyc processors have been gaining quite a bit of market share in the last couple years as well. They've become popular enough that AWS even now offers Epyc EC2 instances.

I obviously read the wrong stuff. So the Ryzens don't show, but the Epycs are making inroads? Ok, they have got to be profiled differently. What are the essential differences?

Ryzen doesn't show in the server market because Ryzen's are marketed as laptop/desktop chips exclusively. Epyc is the branding for Zen servers. They use the same cores as Ryzen (Zen, Zen 2, Zen 3) but have more cache, more PCIe lanes, have support for ECC memory, can use far more channels of memory, etc. Basically everything that Intel does with it's Core architecture to make their Xeons is exactly the same as AMD does to their Ryzen architectures to make Epyc.

Ryzen - Consumer desktop/laptop - akin to Core
Ryzen Pro - Business desktop/laptop - akin to Core w/ V-Pro
Threadripper - HEDT/Workstation - akin to Core X
Epyc - Server - akin to Xeon

All the above has been gaining popularity since they were released. Ryzen gained popularity the fastest. First generation Epyc wasn't all that big (Enterprise is slow to accept new things for fear of issues), but with the Zen 2 and now 3, Epyc processors are gaining steam, doubly since they offer more cores/threads per socket than Intel can currently offer, and usually at the same or slightly lower TDP.

Ok.

After a long silence on hardware specs in the hardware forum, I compared AMD's Ryzen & Epyc profiling myself

a Top of the range Ryzen has

• Greater base frequency, and therefore single threaded cpu speed.
• Up to 32 cores
• Top of the range GPU
• Greater Memory Bandwidth

A top of the Range Epyc has

• Up to 64 Cores/128 threads
• No GPU, allowing space for the extra cores
• A greater variety of base and turbo frequencies
• More PCI lanes = more I/O potential
• Bigger caches (I think)
• More Memory Lanes

So your ultimate beast PC might well include a 64 core Epyc and a Nvidia GPU! But that Epyc is not cheap. It's around US$7000, US$4000 from China (presumably bought in bulk) or UE$8800 from Italy

If you're going for a pc, not server specific, you'd probably want to go Threadripper, not Epyc. While it's only Quad channel memory instead of 8-channel, and ECC functionality is questionable, at best, it supports higher frequencies than Epyc while supporting more cores than Ryzen with double the ram bandwidth (quad channel vs. dual channel). And while expensive, NOWHERE near as expensive as Epyc.

Agreed. I'm not going for anything just yet, unless I land a bargain that I can't refuse. Being a hardware head, I can see that the Xeon/Epyc is profiled for large numbers of busy processes (= a workhouse) more than desktops, which are smaller scale sprinters. And in terms of expense, a woman with luxurious tastes or an Engineer specifying components are up there together!

Lastly, to correct myself, threadrippers are now offering 64 cores. Personally, I don't want/need that. I certainly don't want to pay for it.

No, but if you're doing something that's going to be thread & ram intensive, Threadripper can have major advantages over Ryzen even with the lowest level 24-core Threadripper 3960x vs. the 16-core Ryzen 3950x due to quad-channel memory vs. dual-channel. But if you just needed 32 or less threads, the 3950x/5950x (if you can find it for sale ANYWHERE near MSRP) offer the best value.

I'm not a big-time CPU or server user. But being an ex-hardware head, I can see that spending well on my next motherboard/cpu will effectively be a future-proof purchase, because peripherals may change, but something decent now will not become obsolete with time. I gather one of the major obstacles is that manufacture less than 7nm runs serious issues with FET gate thickness, as just one electron or hole sneaking through in ten zillion transistors ruins things. Frankly, I didn't know if they'd make 5nM (which they did). Each reduction is going to be a major, major battle. So I reckon a decent box now means I never have to cough up again, except for peripherals.