"druck"  wrote in message news:qno2oo$759$1@dont-email.me...

On 09/10/2019 20:31, Dennis Lee Bieber wrote:
> > I'd updated both 3B+, 4B2G, and 4B4G to the most recent Noobs Raspbian
> > last week. Today I ran "sudo apt-get update/sudo apt-get upgrade" on
> > systems (main item: an SSL update). While the second 3B+ was processing
> > the "upgrade" phase, I plugged in the 4B2G. I was able to run the same
> > update/upgrade, shutdown, swap with the 4B4G, update/upgrade (needed two
> > updates -- NTP had not synched the time and it rejected a repository for

The lack of a battery-backed (or even capacitor-backed) real-time clock is a
nuisance if the Pi reboots and there isn't an internet connection by the
time the Pi needs it - if it takes longer for the router to boot and
establish a connection than it takes the Pi to boot. I run a weather-station
recording package (Cumulus) on my Pi and occasionally after a power cut the
Pi has booted up with the wrong time (eg 30 or so minutes in the past) so
I've had readings every minute marked with the wrong time which leads to a
graph that goes back in time (!) until NTP eventually syncs the Pi's clock
(*). It happens so rarely that it's not worth devising my own external
battery-backed RTC solution, but it's annoying when I have to go in and
hand-modify the times in the log files and restart the software so it reads
and displays them on its graphs.

> > being invalid [the R-Pi was using the last boot time, and the repository
> > was dated five days in the future ]), and shutdown... ALL BEFORE the
> > 3B+ finished its upgrade of the same files.
> >
> > Either that 3B+ has a very slow SD card, or a distinct speed difference.

> The Raspberry Pi 4's SD card reader is many times faster than on previous
> models.

Have you found that access to the system drive and swap area is affected by
the slower SD access of the 3B+? I also use my 3B+ Pi as a PVR (a video
recorder) and I was impressed that the software I use (TVHeadend) was able
to write several overlapping programmes, including in HD, to the SD card
without any apparent bottleneck. I only switched to recording to USB hard
drive because I needed more space than on a 32 GB SD card.


(*) Sometimes it has taken maybe 20-30 minutes before the timestamp of the
weather readings is correct - I'm not sure whether it's NTP that is taking
that long to set the system time correctly, or whether it's the
weather-station software that isn't noticing that the system time has been
corrected. Both times it's happened are when I haven't been around, so I've
been able to look at the system time (eg using the date command) in the
interim.

--- SoupGate-Win32 v1.05