On 24/09/2020 09:21, Jan Novak wrote:
> Hi, my raspi4 is booting and running from an USB-SSD Harddrive
> connected with no additional power for the harddrrive.

I've been running that combination on the Pi 3B, 3B+ and 4B for years
without issues.

> With "stress" i simulate some stress for CPU / IO and RAM. At the
> moment (first 6 hours), everything works as expected. The
> measure_volts shows me ~ 0,84V and CPU Temp ~ 84°C (at stresstest)m 
> without stress ist is at 58°C.
> 
> Is this OK for 24/7 running?

During the stress test it will be thermally throttling, which shouldn't
do any harm for short periods, but either a large passive heatsink or a
small fan will prevent it getting that hot, and avoid the performance
drop off.

58C for normal running is fine 24/7.

---druck

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