AMD has updated the Ryzen product pages to be more specific about what "max boost" means: "Max Boost Clock is the maximum single-core frequency at which the processor is capable of operating under nominal conditions."
Interestingly, AMD removed that popup for a while, before bringing it back with slightly different wording (see
Ryzen specifications). It now says:
"Max boost for AMD Ryzen processors is the maximum frequency achievable by a single core on the processor running a bursty single-threaded workload. Max boost will vary based on several factors, including, but not limited to: thermal paste; system cooling; motherboard design and BIOS; the latest AMD chipset driver; and the latest OS updates."
AMD's Senior Technical Marketing Manager, Robert Hallock, further clarifies, in his recent blog post on the issue (see
AMD Community Blogs), when you should and should not expect to see the Max Boost frequency:
"Following the installation of the latest BIOS update [with AGESA version 1003ABBA], a consumer running a bursty, single threaded application on a PC with the latest software updates and adequate voltage and thermal headroom should see the maximum boost frequency of their processor. PCMark 10 is a good proxy for a user to test the maximum boost frequency of the processor in their system. It is fully expected that if users run a workload like Cinebench, which runs for an extended period of time, the operating frequencies may be lower than maximum throughout the run."
Note that, unlike previous generations of Ryzen, Max Boost now means max. It is not the sustained single-core frequency, and there is no longer any extended frequency range (XFR) beyond the Max Boost number printed on the box.