The HP Spectra X2 is a Core m affair with models sporting m3, m5, or m7 CPUs; up to 8gb RAM, and 512gb storage plus LTE, USB-C, Wacom pen support with 2048 pressure levels, and 3D RealSense rear cameras but only the standard front camera so goodbye Windows Hello. Full review on ARStechnica HP Spectre x2 review: All the quality of the Surface Pro, hundreds of dollars less The Skylake Core M parts seem to be better balanced than their predecessors. In extended workloads, their low power rating limits their performance; the processor can sustain a speed of around 1.2GHz (depending on the exact model). But for short bursts, such as the initial hit you take from loading a new webpage or starting a new app, the processor can ramp up to 3.1GHz, making it every bit as quick as any other Skylake processor. But if you think this low-power processor is going to mean better battery life, well, that's a little more complicated. We ran two battery life tests. One cycles through webpages every fifteen seconds, intended to be representative of a browsing session where you load a page and then read it for a while before moving on. The other is a heavier burden; it runs a WebGL animation continuously. These tests have different performance profiles. The first has a burst of activity every fifteen seconds but allows the processor to idle in the gaps. The second keeps both processor and GPU continuously operating. In the first test, the x2's performance wasn't too impressive. Both the x2 and the Surface Pro 4 have 42Wh batteries, but the Surface Pro 4 (with a Core i5) could manage 491 minutes in this test. The x2 with its Core m7 only hit 430 minutes. The lower power processor lost. But perhaps that's not terribly surprising: in this benchmark, both processors idle most of the time, and they both idle at closer to zero watts. In the second test, however, the situation was different. The x2 managed 260 minutes, compared to Surface Pro 4's 217. In this sustained workload, the Surface Pro 4's processor can run at a sustained higher speed, drawing more power. The x2, in contrast, slashes its clock speed to keep inside its low power envelope. This means that the x2 doesn't go as fast and animate as smoothly as the Surface, but it extends its battery life. Accordingly, it's not really appropriate to think of Core M as the low power, long life option. Rather, the low power rating means it makes a different trade-off under sustained workloads. It's slower, but it lasts longer.