Then there's something physically wrong with it. My M1 MBP - which is near-constantly at 100% CPU doing neuroimaging tasks - gets about 9 hours. If I'm not running high-cpu tasks and just web browsing, I've gotten 13-18 typically (e.g., two full days of use between charges).
>If I'm not running high-cpu tasks and just web browsing,
You state this as if they are 2 different things. Sadly, more and more shittily designed sites are using more and more resources. Whether that's just a poorly written bit of JS or a maliciously written bit of JS, web browsing is becoming more compute intensive.
I believe the M1 is much better at computing JavaScript as well. Comparable intel x86 CPUs have 60% more branch misprediction during JS benchmarks and ARMv8.3-A added the processor instruction FJCVTZS (Floating-point Javascript Convert to Signed fixed-point, rounding toward Zero).
Especially due to the better branch prediction, the M1 simply does quite a bit more web browsing with fewer VPU cycles used, thus less power consumption.
