[PROBLEM] Insufficient power

[feflo]

Hello to all. 

I am feeding a Raspberry Pi (3 or 4) by a lab power supply (15V, 3A without time restriction - declarated, verified by measuring), but in Moode both of RPis showing "0x0005 (or something like this) -" throttling was occured, curently throttling", etc. - real consupting current is 0,7 - 1,1A (RPi 4) at peak. Where can be a problem, if with the same power cable hooked up in to the cheap SMPS, there is no issue (btw - same error with genuine RPi 4 3A power supply from Moode 8 and something and different Pis (3B, 3B+, 4)).

Voltage set on lab. PS - 5,22V (it is stable all the time, and PS is linear, not switching).

Thank you.

[Tim Curtis]

The observation "if with the same power cable hooked up in to the cheap SMPS, there is no issue' suggests some sort of oddness or incompatibility with the other power supply.

I use official Pi-4 3A supplies on various model pi's including Pi 4 an no issues with throttling.

[grumbleweed]

I've run moode on Pi 2, 3 and 4 all on 2.4A psu with no problem, with a 2tb hdd powerd via usb.

[Falco]

Hello to all. 

I am feeding a Raspberry Pi (3 or 4) by a lab power supply (15V, 3A without time restriction - declarated, verified by measuring), but in Moode both of RPis showing "0x0005 (or something like this) -" throttling was occured, curently throttling", etc. - real consupting current is 0,7 - 1,1A (RPi 4) at peak. Where can be a problem, if with the same power cable hooked up in to the cheap SMPS, there is no issue (btw - same error with genuine RPi 4 3A power supply from Moode 8 and something and different Pis (3B, 3B+, 4)).

Voltage set on lab. PS - 5,22V (it is stable all the time, and PS is linear, not switching).

Thank you.

Hi, i had the same issue with a RPi3 and an iFI audio iPower, it had an output of 2,5A. Similar issue with a microusb adapter for the RPi4 psu but found out these adapter often have a power limitation.

In the end I bought an original Raspberry psu for the RPi3 and now the issues are gone.

[feflo]

.Thank you all, but as I wrote - same behavior with the official RPi 3A SMPS.

It is weird, but i will try to dig deeper and if will find a solution (or reason why this is happening), I will publicate results and maybe this will help to someone (for now i found only this : https://forums.raspberrypi.com/viewtopic.php?t=290853 ).

[DRONE7]

Do you use the same cable from the SMPS to the Pi as from the Linear supply ?

Possibly not...and if not then..
Up-rate the cable from your linear supply to the Pi.
Your symptom is known from several other power supply threads in the RPI forums where the supply is sufficient but the cable used is insufficient for the current required.

[Nutul]

You must have some peripheral attached for it to not work on so many different PSUs... so, what is it?

[feflo]

@DRONE7 - i used the 1 and the same cable (of course - i am stupid, but not so much maybe :-)) - official Xiaomi 6A 1m cable (buyed from local brand dealer)...

@Nutul - i had attached to LPS an DAC together with RPis, but DACs power consuption is 1,5W (0,3A/5V), and (as i wrote) current required by both this devices together was 1,2A at peak (lab LPS is able to deliver 3A stable and without time restriction - even a passive cooler was heated up only to 40 deg. C after a couple of hours). I tried it with RPi alone too - same behavior.
With official RPi 3A SMPS was powerred RPi only.

Otherwise, i tried to set up voltage lower (previosly setuped to 5,2V) - into 5V and situation goes better (i suspect it will have something to do with the brown out detector in the firmware).

The strangest thing is that the same problem -"throttling situation" - was repeated with the rpi3, which basically has significantly lower power requirements.

Maybe there is some issue with lab LPS, but why official RPi 3A SMPS shows exactly the same behavior (without any other devices hooked up)?

Now i am powering RPi from 5A on 5V SMPS, but this is not a solution for me.

I will made another attempts.

Sorry, I don't want to bother you with this, but I would like to know the reason why this is happening.

[Tim Curtis]

@DRONE7 - i used the 1 and the same cable (of course - i am stupid, but not so much maybe :-)) - official Xiaomi 6A 1m cable (buyed from local brand dealer)...

@Nutul - i had attached to LPS an DAC together with RPis, but DACs power consuption is 1,5W (0,3A/5V), and (as i wrote) current required by both this devices together was 1,2A at peak (lab LPS is able to deliver 3A stable and without time restriction - even a passive cooler was heated up only to 40 deg. C after a couple of hours). I tried it with RPi alone too - same behavior.
With official RPi 3A SMPS was powerred RPi only.

Otherwise, i tried to set up voltage lower (previosly setuped to 5,2V) - into 5V and situation goes better (i suspect it will have something to do with the brown out detector in the firmware).

The strangest thing is that the same problem  -"throttling situation" - was repeated with the rpi3, which basically has significantly lower power requirements.

Maybe there is some issue with lab LPS, but why official RPi 3A SMPS shows exactly the same behavior (without any other devices hooked up)?

Now i am powering RPi from 5A on 5V SMPS, but this is not a solution for me.

I will made another attempts.

Sorry, I don't want to bother you with this, but I would like to know the reason why this is happening.

Maybe you have a defective Pi PSU?
Try a replacement or new unit.
Most of my Pi's use the official 3A supply and never any throttling.