> ARM64 is starting to catch up in performance for a much lower price

Why do you say "starting to"? arm64 has been competitive with ppc64le for a fairly long time at this point

adrian_b 30 minutes ago | parent | next [-]

I do not think that I have seen any public benchmark for more than a decade that can compare ARM-based CPUs with IBM POWER CPUs.

The recent generations of IBM POWER CPUs have not been designed for good single-thread performance but only for excellent multi-threaded performance.

So I believe that an ARM CPU from a flagship smartphone should be much faster in single thread that any existing IBM POWER CPU.

On the other hand, I do not know if there exists any ARM-based server CPU that can match the multi-threaded performance of the latest IBM POWER CPUs.

At least for some workloads the performance of the ARM-based CPUs must be much lower, as the IBM CPUs have huge cache memories and very fast memory and I/O interfaces.

The ARM-based server CPUs should win in performance per watt (due to using recent TSMC processes vs. older Samsung processes) and in performance per dollar, but not in absolute performance.

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mbreese 2 hours ago | parent | prev [-]

I thought PPC was supposed to be highly performant, but not very efficient. I didn’t think ARM (at least non-Apple ARM) was hitting that level of performance yet. I thought ARM was by far more efficient, but not quite there in terms of raw performance.

But I could be wrong… I’m going from a historical perspective. I haven’t checked PPC benchmarks in quite a while.

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kjs3 30 minutes ago | parent [-]

Are you guys sure you're not confusing product lines? PPC is a PowerISA architecture, but hasn't been pushing desktop/server level performance for, what, almost 20 years? It's an embedded chip now, and AFAIK IBM doesn't even make them any more. Power (currently "10th gen"(-ish)) is the performant aarchitecture, used in the computers formally known as i-Series, formerly known as RS/6000. It's pretty fast, not not price competitive. They aren't really the same thing.

	▲	adrian_b 13 minutes ago \| parent [-]
		"PowerPC" was a modification of the original IBM POWER ISA, which was made in cooperation by IBM, Motorola and Apple. Motorola made CPUs with this ISA. Apple used CPUs with this ISA, some made by IBM and some made by Motorola. While Motorola and Apple used the name "PowerPC", IBM continued to use the original name "POWER" for its server and workstation CPUs. Later IBM sold its division that made CPUs for embedded applications and for PCs, retaining only the server/workstation CPUs. However, nowadays, even if the official IBM name is "POWER", calling it "PowerPC" is not a serious mistake, because all the "PowerPC" ISA changes have been incorporated many years ago into the POWER ISA. So the current POWER ISA is an evolution of the PowerPC ISA, which was an evolution of the original 1990 POWER ISA. It is better to call it POWER, as saying "PowerPC" may imply a reference to an older version of the ISA, instead of referring to the current version, but the 2 names are the same thing. PowerPC was an attempt of rebranding, but then they returned to the original name.