With identical parameters
Laptops on Snapdragon X platforms will go on sale from June 18, and then we will finally see third-party tests. In particular, we will be able to check the claims about the phenomenal autonomy of such laptops. But some things can be understood already now. For example, Dell specifies the battery life for its new XPS 13, and this laptop is available in both Snapdragon X Elite and Core Ultra versions.
The Snapdragon SoC model is claimed to last up to 27 hours of video playback. And that's 9 hours more than the same laptop with the Core Ultra 7 155H. That is, the Snapdragon X Elite model is 50% more battery-efficient. The batteries in the laptops are also identical (55 Wh).
Thus, the recent tests were apparently true, and Snapdragon X laptops are significantly more battery-efficient.