What is the reasoning behind disabling ASPM in Quarch Idle bench?
Isn't that what gives extremely low power consumption while idle?
For desktop use, ASPM isn't critical. It can reduce power use, but only by up to 1~2 watts in most cases (4W maybe on a "bad" drive with little to no power management), and it can create some slight additional latency at times. If you enable ASPM, in theory it just allows all SSDs to be put in a deep sleep state where they're waiting for the command to wake up, which means most will drop to ~50 mW of power use.
By leaving ASPM off, we get to see the "still powered on while idle" power use, which is where an SSD will sit if it's getting periodic (like once every 5~60 seconds) accesses. In such a scenario, as I understand it, the SSD won't actually enter deep sleep states and thus continues to draw its idle power. On a desktop, this is still generally not a big deal, but in a laptop, if your SSD keeps getting accesses that limit the deep sleep time, it can end up drawing 1~2 watts of power for a few minutes before going back into deep sleep mode — repeated every time there's an SSD access. That can have a real-world impact on battery life.
On the Steam Deck, where I've previously done battery life testing with ASPM enabled (because AFAIK you can't disable it), basically every SSD ended up providing the "same" battery life because the drives would just enter deep sleep mode. Over time, changes to SteamOS improved battery life a bit, but without running a battery test that was actively using the SSD on occasion, everything looks identical. In practice, deep sleep modes will basically have the same end-user experience (even a 25 mW vs 100 mW difference just won't really matter, despite the latter being 4X higher), so looking more at the idle but not deep sleep power use makes sense.
In terms of power use, I'd consider efficiency the most important metric, then average power, then idle power, and finally the max power is only tangentially interesting (depending on how often a drive comes near that level). For laptops, idle power does become a bit more important, but the real consideration is how much power a drive needs on average while in active use, because that impacts cooling considerations. Drives that average over 5W of power when active can run very hot if placed in a laptop, and getting average power use to 4W or less is generally the goal.
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