No mention of methodology there. In the review of the M1, it looks like they reported some numbers from software estimates (never particularly accurate, especially for cross-platform comparisons), and some measurements of wall power (ignoring the battery, which actually matters for peak power consumption). The one AMD 5800U review I checked seemed to be mostly using wall power measurements. Their methodology article does not really provide any further detail ( https://www.notebookcheck.net/Our-Test-Criteria.15394.0.html ). Every plausible way of producing the numbers in the comparison chart from the data they collect and present in their individual laptop reviews leaves them at risk of systematic errors on the order of several Watts.