| Interesting, I kind of expected AMD to be first out the gate with one. From : http://www.zdnet.com/applied-micro-canonical-claim-the-first... "The X-Gene is an ARMv8 64-bit Server-on-a-Chip package running at up to 2.4GHz. It combines 10/40 Gigabit mixed signal I/O with what AMCC calls an enterprise-class memory subsystem. Compared to x86 architectures, AMCC claims that it delivers four-times the processor density while using less than 50 percent of the power and delivering comparable-to-better overall performance." The picture shows multiple cores, but not how many. What struck me though is that they are pitching "density and less power", presumably they mean you can put twice as many of these servers in the same power foot print that you currently put x86 machines and get 8x (4x * 2) the computing power. In case you are wondering, that is a 'super computer' pitch, it tickles the pain points of these arrays of super computers, but sadly it does not hit the 'web services' pain points. I'd love it if they said, 1TB of ECC protected RAM, dual 10G ethernet, and 32 full speed independent 6GB SATA channels on each server unit. That would help me make a more responsive web infrastructure. |
The cores we've got are still heavily optimized for single thread performance, because that's what the market demands. Even embarrassingly parallel domains like web serving have increased latency, and Amdahl's law is a problem for most real world programs. The penalty paid for this is high, due to diminishing returns due to caches, complex architectures, and (roughly quadratic) power increases due to higher clock speed.
Ignoring the obvious ARM versus Atom low end comparison, Intel is readying Knight's Landing, their 2015 Xeon Phi product. It's going to include 72 Atom cores, with 288 threads, and be able to be socketed in standard Xeon motherboards.
That's 1152 Atom threads on one commodity(ish) server (and the first time I've ever used a calculator to determine the thread count of a server), and it looks a hell of a lot like the picture being painted by many ARM vendors. Many lightweight cores, great power efficiency and peak performance, and most likely not necessarily suited to latency sensitive tasks.
I don't think it's about ARM versus x86 at all, it's more about a new strategy for computation. Intel can't transition its traditional x86 processors over to the new model, so they're starting to make Atom a first class Xeon product (both with low power standard Atom chips already released, and the Xeon Phi).
The market will shift the other way too - we're going to see ARM processors from multiple vendors that rival at least AMD's x86 offerings in terms of performance per core. And power consumption, too.
After that, there'll be products on both ends of the spectrum from both architectures, and then maybe we can start to move past the false dichotomy of ARM having efficiency and x86 having performance.