Sleep is such a finicky thing which requires all parts of the system to do it right.
My desktop lost the ability to sleep because I guess the nvidia drivers have decided that you are wrong to want to put things to sleep.
Looks like Framework has started heading this direction too, which is nice to see.
Apple's storage controller is not even a PCIe peripheral internally, so it's saving power and latency cutting out that interface, even when it's active.
I'm guessing Intel/AMD could integrate a single SSD controller that OEMs could use for a specially socketed SSD?
I'm not familiar enough with SSD controllers - but what limits would this introduce. I'm thinking they can't be totally generic - with any NAND chips, any layout, 1-4 chips and TLC or QLC NAND - any capacity etc. It strikes me it would be limiting - you would become restricted to a a small subset of SSDs, maybe not forwards compatible with newer NAND chips etc.
I'd think only the minority of PC Laptops would make sense to have this - ones with soldered SSDs - and I don't know many of these. So Intel/AMD would need a big push to integrate any controller. Maybe Windows ARM laptops, if the controller makes a big enough difference, will do this. I'm curious now if any Snapdragon devices are doing this already.