Because the ring bus architecture doesn’t support avx512 but ring bus has better latency which is why many prefer it for gaming or audio production work.

This is still using the skylake microarchitecture from 2015. I'm sure if Intel were shipping the design they wanted to be shpping it would have AVX512.

Perhaps this tells us something about the relative size of the high-performance desktop market compared to the market for MacBook Pros, which have Ice Lake CPUs with AVX-512.

Why speculate? If we take i9s to be considered par equivalents to high-end CPUs we find in MacBook Pros, and the market distribution of cheap to expensive CPUs is similar in both desktop and notebook segments, then we can simply look at earnings reports.

https://s21.q4cdn.com/600692695/files/doc_financials/2019/20...

From page 34:

6% of Intel's Desktop platform volume is $705Mn, so total volume is $11.75Bn. 5% of Intel's Notebook platform volume is $1080Mn, so total volume is $21.6Bn.

So the desktop market is slightly larger than half the size of the notebook market, but $12Bn is a lot of money to leave on the table then turn your back to. Especially since an aged microarchitecture threatens all CPU-related revenue streams.

What desktop applications use AVX-512?

If it is more available, more would