POWER has been better performing than intel since basically 1990, though intel's tick/tock cadence and trading blows in fab tech have kept things interesting. That shouldn't be surprising since POWER is ultra focused on the high end and intel is fending off attacks from the low end and never had good long term thinking on the high end.

The reason every server isn't POWER is: ecosystem. For any random company, switching archs for anything less than a multiple factor gain is a daunting multi-generation proposition. For a hyperscaler like Google the bar is a lot lower but you need a compliant vendor that will do a lot of the long haul platform work. IBM's been trying to establish that for many years and is just about to pull it off. Supply chain is also important, hyperscalers have come to expect buying and building systems a certain way and IBM will now just sell chips or even the IP for you to fab yourself. And of course the total cost calculus: capex, and opex in the form of TDP, support burden.

Google _will_ be using P9 for GPU servers internally. The inflection point for them was I/O and memory bandwidth. So, paradigm shift was what was needed to turn a juggernaut.. and that is what adding a bunch of accelerators to your platform is. Intel has no good solution there.

Right. I think HPC will be the first to take on POWER9 since it has some huge advantages with CAPI and PCIe v4. Outside of that, it will take some run time to convince the larger cloud providers it's useful.

I believe POWER9 has the ability to be either big or little endian as well, so that helps for compatibility issues, and it's just a matter of whether your application can compile.