I'm somewhat confused. Apple is capable of making realistic claims when it comes to battery life, as they are designing the entire laptop themselves. AMD, however, is not. This Ryzen 9 7940HS will exist in laptops that vary significantly in terms of what size of battery pack the laptop is going to be combined with. Different manufacturers are going to use different memory modules, different storage modules, different WiFi modules etc. All of these things are going to affect battery life. Especially what kind of battery pack is being used on the laptop.
That isn't really all that true. Intel makes plenty of reference designs for motherboards and laptops for the general market. A substantive fraction of the order of magnitude more laptop/desktop offerings than Apple offers that show up in the general PC market are basically just slightly warmed over reference designs that Intel has made.
AMD is behind Intel on the depth and breath of their reference design work, but it isn't zero. As AMD become less and less on the verge of bankruptcy they have gotten much better. They are much further behind on laptop reference design and 'go to market" support than Intel, but it isn't 'horrible' anymore.
However, they do try to lean on a few manufacturers to do tight feedback loop evaluations. [ Similar to how AMD 'outsources' most of the PCH-I/O work ( mainstream I/O USB , etc. ) outside. ]
Also Apple doesn't allow variability on memory modules. That makes them more controlling, not better at predicting performance of a random system in the PC market.
The variability of design myopically focusing on here doesn't necessarily lead to better chips for Apple. Where the case/product design team runs off to paint Apple into a corner the silicon team has to bail them out. Sometimes that is good and sometimes that is bad. Apple doesn't always pick the best corner to paint themselves into. There is a catch-22 , 'dual edge sword' aspect to supplying several reference designs to systems vendors by Intel (and AMD). The system designers then are more motivated to put something on top to drive some distinctive variation to attrack attention in the market. ( some perceived "value add" that others don't). As much as customers want different stuff that is an upside. Apple's "You can't have an xMac" or "can't have a large screen iMac M1 " or etc. doesn't help them cover a larger portion of the PC marketplace.
The Ryzen 9 7940HS, like pretty much every other modern CPU, doesn't come with a fixed power envelope either. So Asus might target a higher power envelope in laptop A, while Lenovo set a different target on laptop B. Power usage will not be static with this CPU.
As long as Asus and Lenovo offer up reasonably accurate specs for their system why is that particularly relevant. Users who are going to spend 99% of the time plugged in docked at a desk may pick systems A and users who are going to spend 99% running on battery will pick system B. Those users can figure it out. It isn't a "land a man on the moon " complex problem to work out.
Apple has an explicitly stated policy of not trying to make everything for everybody. They know they are cutting off some folks from a "best for some subsegment" solution. Apple decides they don't 'need' that subsegment so they just don't do it.
AMD's and Intel's business is about enabling options, not disabling them. They are in a substantively different business. AMD can't be dogmatically all about "everything for everybody" ( they aren't that big) , but they can't also cherry pick too small of a segment to cover either. Intel also is going to have problems with "everything for everybody" as AMD takes a more long term sustainable share of the market. ( some of Intel's 'do everything" was then dictating to folks what to make after they have scooped up vast majority of the profits. That isn't going to work well long term either. Over time top down mandates detached from the market like those tend to paint themselves into a corner also. )
I do not doubt its efficiency. But specific claims on how many hours of battery you will see using this CPU seem strange to me. And one problem with such claims is that you don't have any context on achieving them.
All of these "xx Hours showing video" claims are not about the CPU or vast majority of the GPU at all. It is all primarily based on how good your fixed function video decode logic runs. Apple's , Intel's , AMD's , Dell, HP , etc. running video in benchmarks is less and less about the majority of the silicon in a SoC.
