I'd love to see RISC-V or another open source ISA become the dominant design. But I'm not sure RISC-V is there yet. Companies have been pouring resources into optimizing ARM CPUs for years now, and they're now starting to get to the point where their performance competitive with x86. RISC-V is just getting started. I don't know if there's a RISC-V CPU that's comes anywhere close to the raw performance of higher end ARM CPUs, nevermind x86.
Having said that, I hope AMD doesn't decide not to develop a RISC-V CPU. I'd expect them to have the resources to start working on ARM now, while planning for RISC-V further out.
> I'd expect them to have the resources to start working on ARM now, while planning for RISC-V further out.
I doubt that strategy would work. The problem in the PC space is that there's no Apple-like leader who can boldy drive a change in CPU architecture. Whoever is first out of the gate bears all the risk of the change not catching on. If you lose the bet, you've wasted massive R&D spend to make a lemon. Take a look at the reviews of Microsoft's ARM surface laptops to see what I mean here.
I think there's an opportunity over the next 5 years or so for PC makers to ride the M1's coattails and shift from x86 to ARM. Especially given intel's failure to move off 14nm. But I doubt lightning will strike twice. If windows moves to ARM now, we'll be stuck there for at least another few decades. And the technical argument for RISC-V will be much weaker if ARM rules the roost.
Weirdly the strongest counterargument I can think of is due to electron. Chrome will maintain first class support for any and every popular CPU architecture. So the more that desktop software is written on the web and in electron apps, the easier any architecture transition will be down the road. That and the server space. Linux already supports RISC-V extremely well given how few linux-capable RV chips there are in the wild.
> Companies have been pouring resources into optimizing ARM CPUs for years now
Yes, companies (Apple especially, but also Samsung and Qualcom) have been making optimized ARM CPUs, but those designs remain within those companies. Very similar optimizations could be made on a RISC-V implementation and AMD has proven that they have the ability to make design optimizations.
Having said that, I hope AMD doesn't decide not to develop a RISC-V CPU. I'd expect them to have the resources to start working on ARM now, while planning for RISC-V further out.