12-24-2019, 01:27 PM
(11-22-2019, 11:50 AM)hmuller Wrote:FYIW I am running with MyDigitalSSD SBXe 480 as my file system, with boot on the emmc. (I used a hacksaw to "improve" the adapter) The drive seems to have average performance accoding to my initial phoronix disk benchmark testing.(11-21-2019, 07:49 PM)tsys Wrote: I'm in general somewhat puzzled about how the Pinebook Pro is supposed to stay operational when the battery is low. The discharge cutoff voltage of the battery is specified as 2.75 V. However U3 is just a step-down regulator. Thus it won't be able to maintain VCC3V3_SYS at 3.3 V once the battery discharges below 3.3 V.
That's a great observation. I suspect the 2.75 V is specified to keep it in U3's operational range. With that info, it's prudent to monitor battery voltage while on battery as system behavior may be abnormal below 3.3 V.
I am waiting on the replacement M.2 PCIe NVMe adapter before I install one. I will circle back when I have and share observations. I have my eye on the MyDigitalSSD SBXe, as it is cheap and has an "active power" rating of 3 W with an operating voltage of 3.3 V +/- 5%.
I am able to boot the system with battery at 4%--I haven't tried with it any lower, since I normally would have the machine shutdown at 5%.
I have a rockpro64 on which I am playing with mainline u-boot with TSYS's atf patch (boot on SD or emmc, file system on Samsung 981) I'd love to get that going on this device, too, even if it can't yet boot the nvme directly, since the system seems to boot more quickly.
