Question Why is it so hard for manufacturers, to create a multi core arm processor?

[MeeLee]

Why do we see so few 32+ core arm processors on the market?
If they're that more energy efficient than x86, why does every company that starts up, promising multi arm CPU systems, all die out and never have their product released (beyond an 8 core big little configuration)?
I would think, just parallel connecting a bunch of quadcore arm processors would work, but it doesn't seem to be so easy...

 

[beers]

There are a couple vendors like Ampere Computing with 80c ARM implementations.

Workload wise a faster x86 implementation with less cores is better for >99% of users, plus the market share of x86 in the server space is enormous compared to ones leveraging ARM.

I would think, just parallel connecting a bunch of quadcore arm processors would work, but it doesn't seem to be so easy...

How would you design the interconnect to take the least performance hit?

 

[MeeLee]

All interconnects use pcie lanes, and either create a high speed ring bus using several pcie lanes, or,
deviate each processor from a central processor (star configuration) for a 5 chip (4x quadcore) configuration.
Considering they're arm processors, they probably don't use up a lot of pcie bandwidth, and can do with pcie 3.0 x1.

As far as Ampere, I yet have to see the first seller selling more than just one model online.