[somepig]

No. POWER and PPC are decidedly not the same. the closest they ever came together was the G5's 970.

4xx and 75x were OK for embedded a decade ago, but today they're hot and power hungry. You can use them in devices where you can burn 10+ watts to maintain backwards compact with existing PPC code, but they're way the fuck too hot for a phone.

[classichasclass]

That's true for 32-bit, but 64-bit PowerPC is pretty much synonymous with Power ISA.

[shawnz]

But is that due to ISA differences or just microarchitectural differences?

[temac]

The ISA is mostly the same. I mean, look at https://www.ibm.com/support/knowledgecenter/en/ssw_aix_72/as...

There are differences in details about uncommon instructions, irrelevant assembly language changes, some instructions privileged for one arch and not the other, that kind of things.

But for the bulk of the ISA, it's the same. You probably can create a single userspace binary compatible with both? Not sure but seems doable.

The microarch is likely different but then it is also different between several members of each category, so the word does not really designates the micro-arch, but really the ISA. And then you have other brand names using that, and they are so similar that e.g. Freescale switched from PowerPC to Power while incrementing PowerQUICC II to III. I remember Linux has an eieio macro that just emits the aforesaid instruction for PPC, and actually the opcode does something similar on Power (mbar) and IIRC the assembler is happy to emit it regardless of the ISA.

So it was kind of messy when you reached the differences, but everything was quickly workable and you got use to it. The reference manuals of Freescale are very good and the "[...]Programmer’s Reference Manual for Freescale Power Architecture Processors" EREF_RM often directly points at the few differences with PowerPC.

[monocasa]

On the same process node, PPC chips aren't anymore hot than ARM.