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Re: Raspbian Jessie linux 4.4.9 Severe Performance Degradati

Fri Jul 29, 2016 5:25 pm

@ Moses and others -- understood about the DC-DC converter. So far in testing it looks good, but that might be just luck of the draw as to the battery (integrated DC-DC I'm assuming) that I'm using. Maybe it just doesn't try hard enough .... :D

You are right, of course, the 400mAh battery that I had lying around keeps ti Pi up for way longer than most power outages.

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Re: Raspbian Jessie linux 4.4.9 Severe Performance Degradati

Wed Oct 02, 2019 8:38 pm

dom wrote:
Thu May 12, 2016 11:04 am
Heater wrote:

Code: Select all

$ vcgencmd get_throttled
Okay, the bits in this number represent:

Code: Select all

0: under-voltage
1: arm frequency capped
2: currently throttled 
16: under-voltage has occurred
17: arm frequency capped has occurred
18: throttling has occurred
under-voltage occurs when voltage drops below 4.63V. The Pi is throttled
arm frequency capped occurs with temp > 80'C
over-temperature occurs with temp > 85'C. The Pi is throttled

Throttling removes turbo mode, which reduces core voltage, and sets arm and gpu frequencies to non-turbo value.
Capping just limits the arm frequency (somewhere between 600MHz and 1200MHz) to try to avoid throttling.
If you are throttled and not under-voltage then you can assume over-temperature. (confirm with vcgencmd measure_temp).

So 0x50005 means you are currently under-voltage and throttled.
If you want to be able to support this use case without throttling you will need a better power supply.

Although be aware running a stress test is not typical behaviour. If you never see a non-zero get_throttled value in normal usage, then you may not need to do anything.
Would you explain how, given a code (say 50005, or in my case 20000), you can interpret what "the bits in this number represent?" I'm guessing it's some binary operations, but I haven't used this before

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Re: Raspbian Jessie linux 4.4.9 Severe Performance Degradation

Wed Oct 02, 2019 8:41 pm

Are you really running Jessie from 2016. Or have you just necro'd an old post with something that is entirely unrelated on a different version of Raspbian?
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Re: Raspbian Jessie linux 4.4.9 Severe Performance Degradation

Wed Oct 02, 2019 8:50 pm

"0x" is a prefix used by the C programming language (and others) to indicate that the number is in hexadecimal (you can Google that). When we speak of bit 0 we mean the binary digit with the place value of 1 (2**0). Bit 1 is has the place value of 2 (2**1). Bit 16 is 65536 (2**16). Each hexadecimal digit has 16 different values, which can be stored in 4 bits. 0x5 = 5 = (2**2 + 2**0) = BIT(2) + BIT(0) , so 0x50005 = BIT(18 ) + BIT(16) + BIT(2) + BIT(0).

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