Are USI and MPP supposed to have quite different power drains in “on but idle” state? It seems so. I’ve tested this on a Framework 12 running Fedora 44 in “balanced” power mode; Screen brightness turned to minimal setting, Wifi on, machine doing basically nothing. I have powertop reporting battery use.
with MPP, bluetooth on, I see battery discharge 2.46W
with MPP, bluetooth off, I see battery discharge 2.32W
with USI, bluetooth off, I see battery discharge of 5.20W
(MPP needs bluetooth to report charge state of stylus. The Framework stylus doesn’t support that but Microsoft styluses do. So Bluetooth has some relevance when using MPP)
Otherwise, I have seen no functional difference between MPP and USI (other than that my old microsoft surface stylus does support MPP but not USI).
So, based on these numbers, it would seem that if you have a choice in protocol and you expect your FW12 may spend some time just lying there without it being interacted with; just being ready to be used occasionally (as tablets tend to), then using MPP is a much preferable over USI. Is this inherent to the protocols? Is it the hardware implementation in the FW12? Is it due to the kernel drivers in Linux?
EDIT: After a reboot I have not been able to reproduce these numbers! I’m now getting
with USI, bluetooth off, battery discharge 2.34W
so that suggests the difference is not with MPP vs. USI but there must have been some other unidentified confounding factor. So perhaps there is no difference at all.
My wild guess is that SSD started doing something right when you were checking the power draw. I’ve discovered it tends to get randomly stuck in higher power mode (because allegedly it’s doing some background processing) and it takes somewhere about 2.5W.
Also this is the second post mentioning that MPP requires bluetooth to report stylus battery level which puzzles me because I have Surface Pen 4 which I don’t have paired via bluetooth and I can see it’s battery level. I have this “ILIT somethingsomething stylus” entry in batteries that is 0% on boot and updates when I get stylus close to the screen. I do have bluetooth on but I don’t believe it’s used to transmit the battery level because I didn’t pair the stylus. If I pair it I’m getting two entries for stylus battery.
Ah, thanks. I’ll keep an eye out for when this happens again. An extra 2.5W is almost twice the power draw so it affects how one would plan use of the device. It would be nice to know when it happens and possibly how to avoid it.
For the battery: Under MPP I also get a ILIT battery bar but it’s always at 100%. When I pair my Surface Pro 7 stylus via bluetooth I get a second bar which does change power level. Under USI, I have the ILIT battery bar and it gives varying percentages, depending on which USI stylus has interacted with the screen last.
The reports that USI reports power levels and MPP does not was actually why I tried USI in the first place.
Always 100% hmmm… maybe that’s the case for me? But via bluetooth it also reports 100% though so… yeah, fresh battery things I guess (I replaced it few months ago but I don’t use the stylus too often). I’m not actually sure it showed something lower on previous battery that was somewhat discharged. I could discharge that battery through resistor a bit but I don’t wanna do this because the AAAA batteries are kinda hard to get.
As for the SSD you can look at it’s temperature - in my case it’s like up to 35C and 50C hotspot normally and around 50C and 60+C hotspot when it’s… doing something. I made a post about it some time ago too.