In a recent discussion thread over in Seeking Alpha, one reader commented that PC chip giant Intel (INTC -1.99%) may be able to offset the declines in the traditional PC market by selling processors into two key classes of devices:

  1. 2-in-1 tablet/laptop hybrids.
  2. The oft-rumored Microsoft (MSFT -1.10%) Surface Phone -- said to be able to double as both a Windows Phone and a full Windows desktop machine when docked -- which the reader believes could be powered by either an Intel Atom x3 chip with LTE or a Qualcomm (QCOM -1.85%) Snapdragon 820.

In response to this user, I argued that an Atom x3 chip from Intel would be an entirely inappropriate processor for such a device in fact, I made the even stronger case that it was barely suitable for low-end phones, let alone a Microsoft flagship running full Windows.

Although I received some criticism from at least one Intel bull for this comment, I do think it's worth taking a bit of a technical deep dive to understand exactly why the current Atom x3 product line is unfit for the proposed device.

The performance and features just aren't there
To successfully power a device that can act as both a flagship smartphone and as a fully fledged PC, a mobile chip needs to have very high performance. It can be argued that modern flagship mobile processors offer -- depending on what you compare it to -- "desktop-class" performance, albeit not "high-end desktop from 2015-2016" performance.

However, something like the Snapdragon 820 is certainly much more powerful than even the best Intel Atom processors that power a good chunk of the low-cost laptops and all-in-one PCs that are sold in the market today.

However, the current Atom x3 lineup from Intel is, to put it mildly, not even in the same league as a modern, high-end mobile processor. It's also much slower than even the lowest=end Atom processors that Intel sells into the PC market.

Indeed, compared with a more-than-two-year-old Atom processor aimed at notebook PCs, the top Atom x3 with LTE offers at most 60%-70% of the CPU performance. It has significantly lower memory bandwidth, far less powerful graphics, and support for far less system memory -- just 2 gigabytes, versus 8 GB for the PC Atom.

The Atom x3 also only offers support for display resolutions of 1280-by-800, which is hardly the kind of resolution that one would expect from a flagship Microsoft device. The top Lumia phones from Microsoft feature quad-HD displays -- that is, 2560-by-1440.

I could go on and on, but the point is that you won't see an Atom x3 processor powering a flagship phone that also wants to double as PC replacement.

Intel could still power such a device with Broxton, but ...
Although the Atom x3 from Intel couldn't do the job, I do think that Intel's upcoming Atom x5 and x7 chips based on its Broxton architecture could handle the job. They will probably have solid, although probably not leading, mobile processor performance, as well as enough graphics and display grunt to power a flagship smartphone and even a reasonable Windows desktop experience, and they'll probably be quite power efficient while doing so as a result of being built on Intel's 14-nanometer chip manufacturing technology.

Whether it ultimately will or not remains to be seen, but as Intel has still not provided technical specifications or even performance estimates of this upcoming chip -- it's woefully late to market -- it's hard to make any sort of informed guess there.