Apple looks like they're very close to simply ditching Intel for any mobile product. The A8X used in the iPad Air2 is very competitive with the Broadwell M. http://browser.primatelabs.com/geekbench3/compare/922000?baseline=1061742
Are you talking about Apple notebooks when you say mobile? You can't just dump this thing in a Notebook and expect it to work, everything would have to be recoded for ARM from x86. Absolutely everything from the OS to the applications. Then you would end up with a difference between what a Mac Book can run and what an iMac can run. Microsoft tried this with Windows RT, look what happened there! They could do it but it would take years and they would have to move the whole Mac family to ensure compatability. Then there is the fact that a high end i7 or XEON is going to be hard to get anywhere close to and power users will want that power.
Not if the OS is processor independent, which was certainly the case when Apple made the switch from PowerPC to Intel for their desktops/laptops. When they switched, they had already been compiling OS X to run on Intel processors for five years. That eliminates the scenario you're talking about. Is it really that unlikely that Apple has been doing the same with ARM? Probably not. No guarantee that they have any near term plans to do it, but the performance of their A series chips is already pretty close to Intel mobile.
That is a pretty bold statement seeing as no one has run a full x86 OS on one. Running a full blown OS is quite different to a relatively small mobile OS such as iOS or Android. The processor in your benchmark was the Broadwell Y which is an SoC for tablets or ultrabooks. Broadwell U and Broadwell H are still to come in the mobile segment and they won't be as low powered as the current Y series. Wait until they get benchmarks before jumping to conclusions on how close ARM is to Intel. Yes it is close on the lower power SoC segment but that is just the start of the Broadwell roll out. Rumour is we will see the Core i3/i5/i7 varients of the mobile Broadwell chip in early 2015 so lets wait and see how close the A8X is then! With these proper CPUs running at a baserate above 2GHz 100% of the time I expect A8X to be left behind. And then you have to remember that Broadwell is late, very late in fact. So late that chances are Skylake will actually be released in the same year and being the tock is should bring quite a performance increase over Haswell/Broadwell as it is a new micro-architecture. So not only does A8X have to stand up to the full blown Broadwell chips which have not yet been released but Skylake won't be far behind. Can't see people wanting to put up with slow CPUs in what should be a flagship Apple device when compared to full blown Intel x86 CPUs. Yes A8X is close to Core M but that is the lowest end of the new Intel lineup.
The fact that Broadwell is so late is one of the possible strategic reasons for Apple to eventually ditch Intel. It puts Apple in the position of having to delay upgrades to their products simply because Intel is behind schedule. And the A9 is rumored to come out in the first half of 2015 with the larger iPad. I wouldn't bet on Intel being able to really stay ahead in any significant way for very long. I also don't know why you would think Apple wouldn't be able to release higher performing variants of their own chips, since A8X is a higher performance version of the A8. I've pointed out in the past as well that the Apple A series has typically been outperforming their smartphone/tablet SoC competitors with fewer cores and lower clock speeds. That bodes well for future performance increases.
Look I really can't be bothered to argue with you but all you have is the geekbench score (which doesnt really translate well to real desktop use anyway) scores for 2 low powered SoCs and you are trying to say that the A8X is as capable as a full powered CPU. The A8X is a low powered ARM SoC, it would need a beefy overhaul to make it worthy of really laptop performance and the OS and applications be rewritten to work on ARM. Think of Core M as the Atom of this generation. i3/i5/i7 are the mid-high range CPUs. I'm not saying it will never happen, but not yet.
Errrr, this whole conversation started when cmdrmonkey said that the Core M he was going to be receiving in his replacement Lenovo had performance that was on par with the mobile Sandy Bridge i5.
I think the main question is if Apple is willing to drop performance down for the macbook air in favor of their own custom arm processor? Intel has distinct tiers in their processors. High end high power/low power processors and lower end high power/low power usage processors.
Sandy bridge will be 4 years old in January and 4 1/2 years old when Skylake appears next year. So what your benchmarks shows is that an A8X can nearly keep up with a CPU that had comparable performance to a 4 year old CPU. Also remember the one in that benchmark was a slower 900MHz model with a max turbo of 2.4GHz. The higher end Core M runs at 1.1-1.2GHz with turbo up to 2.9GHz. And again Geekbench isn't really representative of desktop performance.
If you look at the progression of their A series, there's no reason to think they would have a performance drop vs. Intel with future processors. They already have a mobile SoC with over three billion transistors in the A8X. And it's the custom aspect that would make it easier for them to switch, not harder. Custom increases the performance in combination with the OS vs. off-the-shelf designs. Apple keeps emphasizing "desktop class" architecture in regards to the 64 bit A series, so that probably means that the current path they're following is flexible enough to customize for any type of hardware application they choose to use it for in the future. They're not there yet, but it seems like they're probably very close.
Your post suggests that Apple can keep improving the A series SoC but Intel won't keep improving i7s at the same rate? If they stay 4 years apart then Intel will always be the choice for power. AMD hasn't been able to keep up with Intel let alone overtake them and they have been making CPUs for years. Why should Apple be able to crack it all of a sudden?
Intel is always going to be an off-the-shelf solution. That by itself is a performance limitation vs. custom designs that are specifically geared towards a certain OS or hardware configuration. Intel is also using x86 architecture, so that's another limitation. Apple also has a lot more money for development than Intel these days. Plus, as you mentioned, Intel is not necessarily able to keep up with their own roadmap anymore.
Um no it isn't. The CPU is no less powerful because it has to work with 1 or 2 chipsets. Each CPU only has a couple to Chipsets it is compatible with and if you look at motherboard benchmarks each manufacturer is so close to each other in terms of performance the only reason to choose one over another is features/extras that come with the board. An i7 is going to run almost identically across all of the X99 boards available. Intel are on track with Skylake, there is no reason they won't get back on schedule after one slip up.
I'm not talking about the motherboard. Apple can design the annual variants of the A series to their specific hardware and software lineup for that year. They know exactly what to optimize or emphasize for that year, rather than simply having a 3rd party brute force solution from off-the-shelf. Brute force solutions may be fine for some things, but not as efficient for others.