I didn't see anything in the video to substantiate that claim. I went to the section marked "Efficiency Testing", but I don't see any graphs or data being presented. Please provide timestamps of anything in that ~1 hour video you'd like us to see, because there's no way I'm watching the whole thing and even trying to search through and parse the transcript is a bit of a chore, when I don't even know what I'm looking for.
Now, the reason I'm interested is that I've been curious about Lunar Lake, and the lone review on this site really left a lot to be desired. So, I thought I'd head on over to NotebookCheck and see what they found. They reviewed the Core Ultra 7 258V, which seems like it should be within the efficiency sweet spot, as it's a few steps down from the highest spec Lunar Lake model.
In single-thread efficiency (using an external monitor), they got 5.36 points/W on CB 24. This indeed edges out the best AMD model they tested, which was the Ryzen AI 9 365 at 4.01 points/W, but came in below
all of the Snapdragon X models, which ranged from 6.32 to 8.32 points/W, and the Apple M3, which scored a whopping 12.7 points/W!!
In multi-thread efficiency, it got 17.7 points/W, as compared with Ryzen AI HX 370's 19.7 points/W. Snapdragon X
mostly scored higher, with a range of 17.3 to 22.2 points/W. Again, the Apple M3 smashed everyone with 28.3 points/W!
When tweaking with different configurations, the Ryzen AI 9 HX 370 got 25.2 points/W, when limited to just 15 W. The best result showed by the 258V was 19.3 points/W in "whisper mode".
Apple and Qualcomm's efficiency is even more impressive, when you consider that two Snapdragon X models and the Apple M3 beat it on single-threaded performance. So, it really does need that qualifier you used of being the most efficient
x86 CPU. We should probably also mention something about
lightly-threaded workloads, because the stock Ryzen AI HX 370 beat even Lunar Lake's "whisper mode" on multi-threaded efficiency!
Caveats: Cinebench is only one workload. In the article, they did test performance on others, but only have efficiency data for CB24 singe & multi. I should also note that the Ryzen AI 9 HX 370
consistently outperformed the 258V on the web benchmarks, so I have to wonder how its efficiency would compare on those.
FWIW, I didn't dig into the iGPU (but this post is already long enough).