Intel has put out a press release warning anybody working on x86-emulation technology to beware of infringing its patents <https://arstechnica.com/information-technology/2017/06/intel-fires-warning-shots-at-microsoft-claims-x86-emulation-is-a-patent-minefield/>. The article suggests that the timing of this announcement is a warning specifically to Microsoft, and possibly also Qualcomm, over their upcoming release of Windows-10-on-ARM machines. Even if this is so, I’m not sure I agree that “This compatibility makes these ARM-based machines a threat to Intel in a way that Windows RT never was”. The simple fact is that the performance of emulated x86 code on ARM is going to be most politely described as “anaemic”. ARM chips are not the most powerful (they are the most power-efficient), and x86 code is extremely complicated to emulate. Thus, the overheads of the translation layer are going to sap any hope of reasonable speed.