> There are some Core branded CPUs that support ECC, including funnily enough the i3's.

Hell, there are Celeron and Pentium chips that they have it enabled on. Not because they expect desktop users to buy them, but because it allows them to keep their Xeon brand premium while letting OEM's like Dell advertise the T140 "starting at $549" (in a configuration nobody would ever want to buy).

It depends on the use. For a home server or even a small office fileserver, you don't need massive threading capability, and in fact some of those low-core-count parts are fairly highly clocked, which makes them faster.

For example in the 7000 series, the i3 7100 has a 3.9 GHz base clock and you have to go almost to the top Xeon (the equivalent of an i7) to get anything equivalent. And even then it's a turbo, not a base clock, so in principle the motherboard should not let you turbo forever (PL2 time limit may actually be enforced on a server chipset).

Also depending on workload you may not even be able to exploit an increased threading capability anyway, without 10 GbE on the box, or link aggregation capability.

Oh, the i3's are fine for a general small business workload - compared to the socket-compatible Xeon's all they're really lacking is extra PCIe lanes if you need them. That's ultimately what Intel uses to segregate the Xeon and HEDT chips from their mainstream platform, after all.

The Celeron and Pentium chips that have infiltrated entry-level servers are absolute trash though.

There are even Atom chips with ECC: https://ark.intel.com/content/www/us/en/ark/products/97935/i... (for I assume the NAS products that use these?)

It seems like it's mostly any chip that would compete with the Xeon-W gets ECC removed.