Outside of specialized instruction sets, I wouldn't expect major leaps in single-threaded performance from either Intel or AMD for the foreseeable future.

Is that because more cores for a given transistor count better addresses today's computing needs or because we've hit a limit where adding more transistors to a single core doesn't give us more performance anymore?

It's because the design techniques that allow a core to run more instructions per clock -- wider execution units, shorter pipelines, etc. -- also tend to reduce the maximum achievable clock speed.

I have a six year old i5-2500 and a 10700K is quicker but still not twice as fast as the 2500. Its really not worth the upgrade.

https://cpu.userbenchmark.com/Compare/Intel-Core-i5-2500-vs-...

I concur. Dual Xeon E5-2687W here (2×8 pcores, Sandy Bridge). Turbo 3.8 GHz to 3.4 all cores. [Ebay: ~$300 each, mid 2016]

It's still more expensive to buy a brand new Threadripper or 16-core Intel (sic) than this bargain I made some 4 years ago.

I will probably get a Zen 3 platform, once each CCX contains 8 cores (4 is just too limited for my virtualization need, I kinda like that my Xeons are "monolithic").

Obviously this is for programming and shit learning, not gaming, but I can still manage my 60 fps stat with a beefy GPU.

And interestingly enough, the 10600k has a 20% higher base clock than the 4670k (4.1GHz vs 3.4GHz), and a 26% higher boost clock (4.8GHz vs 3.8GHz). That alone probably accounts for the majority of the difference. It's a shame that Intel has barely been able to increase IPC at all in the past decade or so.

In what benchmark?

Cinebench. The Geekbench results are even closer.

Yeah frankly I’m sticking with my old 4th gen Intel too. I’m not doing anything hardcore that needs 10 cores. I’m sure glad about the AMD resurgence and expecting some response from Intel now.

I want to upgrade but there just isn't a reason to yet. I'm still on a 4930k

I mean I'd love to build a new computer, but there's just no point. The only genuinely difficult thing I want my CPU to do is game console emulation, and for that single-thread performance is king and I can't justify the expense for a 1/3 performance increase regardless of how long it's been.