Great question. I’m really curious about what’s exactly happening during s2idle, and whether there’s any potential for improving efficiency.
As a point of reference, my other Linux laptop draws a mere 0.17W in S3, which is 0.3% per hour.
On the AMD Framework 13, it looks like s2idle baseline draw is 0.23W with another 0.05W - 0.9W for RAM, depending on what’s installed. That’s 0.5% - 1.9% per hour.
So yes, selecting different RAM is one way for users to improve suspend efficiency, but it’s difficult to know what to expect before purchasing parts. These consumption specs aren’t advertised.
But I don’t know what accounts for the other 0.23W not attributed to RAM. What hardware remains powered on? How much does the AMD CPU need in its standby state? Is it comparable to a microcontroller on standby, which might be on the order of 1mW?
I’d like to believe that s2idle could approach S3 efficiency if everything has a proper low power state. Is this a realistic expectation? If not, then it’s very unfortunate that we lost S3 on modern hardware.