LOL, you do realize that an m400 can't even beat out a ~3 year old ATOM C2750 in performance right? The performance of the core is literally so bad that the rest of the system isn't a bottleneck in anyway. Yes it is possible to get linear scaling sometimes: when your performance is so bad that its pathetic. Its like in the bad old days when Sun was touting linear performance of their servers, neglecting to mention their linear scaling servers had worse performance than their competitor servers that were like 1/4 the size and 1/4 the price.
And even then its highly likely that they were running embarrassingly parallel kernels with no communication.
I sure you could get a bunch of x86 quarks to scale linearly to some point, I'm also pretty sure that like your example it would still be significantly slower than a ~3 year old Atom. And again, only on embarrassingly parallel toy programs that don't do anything useful.
ARM V8 doesn't provide ANYTHING that assists MP scaling. And it actually lacks significant features compared to x86 for MP scaling.
Oh, and you might not want to get all gung ho about tilera and then post a quote about a different product...
My understanding is that many different SoCs will be designed and developed, for many different purposes; it is not a competition to which is the most powerful, in some sense, but to provide varied SoCs that are fit-for-purpose in different applications.
At present, ARM based SoCs are being used in the field, where there are suitable use-cases, to try them out. More powerful SoCs, for more demanding cases are being developed.
But you know a lot about Intel; can they develop a SoC with, say, 72 Atom cores of some description? - or would it be prone to 'dark-silicon', due to heat dissipation?
ARM have announced that they are developing IP for SoCs of up to 256 cores, presumably for a case like web-serving, perhaps, or network processing. This is enabled by SoC-level design, not by the ISA so much, although that does play a role, so I understand, in the efficiency of some SoCs.
Are Intel developing IP for up to 256 cores on a SoC?