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25 votes
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How to permanently disable swap on Raspbian Stretch Lite

To avoid an error on startup regarding dphys service, try to disable swap on this way: sudo dphys-swapfile swapoff sudo dphys-swapfile uninstall sudo update-rc.d dphys-swapfile remove sudo apt purge ...
Feriman's user avatar
  • 376
14 votes

Raspberry Pi 3 has less than 1GB memory available at OS level

If the output of vcgencmd get_mem arm && vcgencmd get_mem gpu is arm=880M gpu=128M This means that GPU is using 128M. This can be verified/changed in raspi-config Advanced Options, although ...
Milliways's user avatar
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12 votes

How to permanently disable swap on Raspbian Stretch Lite

I used to use sudo update-rc.d dphys-swapfile remove I haven't tried recently so I'll assume that no longer works as you have tried using it. Perhaps try CONF_SWAPSIZE=0 in /etc/dphys-swapfile
joan's user avatar
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10 votes
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Raspberry Pi 3 has less than 1GB memory available at OS level

First of all, I give my best regards to @Milliways for suggesting to check 2 simple commands. vcgencmd get_mem arm && vcgencmd get_mem gpu Where is the missing 128MB memory? Even if both ...
vaha's user avatar
  • 1,240
9 votes
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Extra 16M memory on Pi2/Pi3

The Pi has a 30-bit (1024MB) address space (the top two bits are used for caching aliases). A small amount of one of the aliases is used for gpu peripheral access. The arm accesses gpu memory space ...
Michael Wilcox's user avatar
9 votes
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C++ cout output on RPi 3B

ostream class has no methods to print volatile pointers, and a volatile pointer cannot be converted to a regular pointer without an explicit cast. However, any pointer can be converted to bool: every ...
Dmitry Grigoryev's user avatar
6 votes
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More Memory on Raspberry Pi

I was wondering if there was any way to allow more ram Not more physical RAM, but you can increase the amount of system memory by using swap, which is a region of secondary storage. Traditionally on ...
goldilocks's user avatar
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6 votes
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Memory Limit of Python3 in Raspberry 3

Your kernel could be build with 2G/2G memory split (giving 2GB of virtual address space to the kernel and leaving another 2GB for the applications). You can check that in kernel config: zcat /proc/...
Dmitry Grigoryev's user avatar
5 votes

Unable to set GPU memory split on Raspberry Pi Zero W

Thanks to the forums over on raspberrypi.org I was able to find out the answer to this, so I am sharing it here for future reference... ANSWER: The 128M of GPU RAM is still being reserved because I ...
MrChips's user avatar
  • 983
5 votes

How can I install keybase (and dependencies) without running out of memory?

create a swap file with 4 GB of space: This was my problum when installing docker i had to create a swap file and it worked same error code, so let me know if this works! Source: This Post ...
User98764431's user avatar
4 votes
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Are Rpi1B 256MB / Rpi1B512 interchangeable using *the same* SD/card (Raspbian)?

I would expect the OS to be "smart" enough to "adapt" to the extra (or less) amount of RAM. But does it? Yes. There are only two basic forms of pre-compiled kernel, one for the single core ARMv6 ...
goldilocks's user avatar
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4 votes
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Raspberry PI 3 Increase Gpu Memory to 944

This is useless as you don't seem to run GPU RAM heavy OpenGL applications. You don't need more than 128MB GPU RAM to run videos smoothly as the hardware decoder will use only a fixed amount. So ...
kwasmich's user avatar
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4 votes
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What is the memory in the DS3232 RTC for?

@Dougie is absolutely correct, you can to whatever you want with this memory, and it will survive a power cut of the main supply as long as the battery is OK. The reason for such memory is that in ...
sweber's user avatar
  • 516
4 votes

How to write protect in DS2431 Maxim EEPROM using Raspberry Pi

It is very helpful when working with electronic devices to read their data sheet. The electronics equivalent of RTFM, "Read the fine manual" is RTFDS. It will explain the features and electrical ...
justinjt's user avatar
3 votes

regarding how to measure memory usage on raspberry pi for a specific program

You may want to start by running top and locating your program in the list. It will look similar to this: As you can see, there are 3 different memory metrics, each with its own gotchas: VIRT - this ...
Dmitry Grigoryev's user avatar
3 votes

Why do I have so many RAM disks?

Short answer: it is just a fdisk peculiarity on latest versions. Alternatively you could also use parted and lsblk. Extracted from this thread at AskUbuntu: On later versions of fdisk the ...
Sopalajo de Arrierez's user avatar
3 votes

Can Compute Modules provide clustering and high availability?

While not doing this with compute modules, I have 6 PI3's running together to test HA setups (database cluster sometimes, load balanced nginx servers other times). It's way cheaper to buy 6 pi's (and ...
Michael's user avatar
  • 326
3 votes
Accepted

Raspberry Pi with flash memory?

The compute module has upto 32GB eMMC flash memory on board. You will need some form of daughter board though: https://www.raspberrypi.org/products/compute-module-3-plus-32gb/
CoderMike's user avatar
  • 6,997
3 votes
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RPI3B+ Chromium Freeze - RAM Swap

The memory installed on a Raspberry Pi is directly soldered and is not intended to be replaced or extended. Looking on the web, while there are quite a few posts asking for a method to add RAM, all ...
Richard Chambers's user avatar
2 votes

When does the OS kill an application?

The Linux kernel "overcommits" memory, that is when your process allocates virtual memory it does not immediately allocate physical memory or swap space. The physical memory is only allocated when the ...
Peter Green's user avatar
  • 6,486
2 votes

What is the optimum split of main versus GPU memory?

From my experience, 8-16MB for just terminal. 20MB for 800p GUI 24MB for 1080p GUI 32MB for 1440p GUI 64MB for <1080p youtube videos 128MB for 1080p youtube videos 256MB for 4k videos (more than ...
ProDigit's user avatar
2 votes
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EEPROM Raspberry pi HAT read

The HAT spec basically calls for the EEPROM to be an I2C device slaved on address 0x50 (which is more-or-less an industry default). At boot time, the device tree layout and other stuff is read from ...
BJ Black's user avatar
  • 576
2 votes

Can I have one raspberry pi access the memory of another pi?

You could possible create a RAM disk on one Raspberry Pi and share it with NFS. The other Pi could access the disk. See this for how to do it on Ubuntu. I see no reason why it wouldn't work on ...
jogco's user avatar
  • 497
2 votes
Accepted

Will linking the clock file to an in-memory file lower the wear on the SD card?

Do NOT WASTE YOUR TIME worrying about SD card wear! This is one of the urban myths. Any decent card will have wear levelling. If you did REALLY want to minimise writing to the card this file would ...
Milliways's user avatar
  • 60.5k
2 votes

What is the memory in the DS3232 RTC for?

The non-volatile RAM (while the battery backup is OK) is there for whatever purpose you like. It's not secure storage, it's easily overwritten (by a root user) but it's just a spare few bytes which ...
Dougie's user avatar
  • 5,321
2 votes

What is the correct way to use /dev/gpiomem with mmap to get access to Raspberry PI3 peripherals

/dev/gpiomem only gives access to the GPIO register addresses. To gain access to the PWM registers you need to use /dev/mem which requires root access. If you try to access hardware PWM with ...
joan's user avatar
  • 71.2k
2 votes
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Python process Memory error

If you don't care about execution time, increasing your swap size from 100MB to a couple of GB will triple the amount of available memory. Projecting your current code efficiency (1 GB or RAM needed ...
Dmitry Grigoryev's user avatar
2 votes

Running x86 Windows app on a Raspberry Pi 3B

I have run some Delphi Win32 Apps on a Pi using Exagear Desktop and Wine. In some of them I couldn't get the sound working (AFAIK it depends on the exact VCL/CLX sound components the authors have used)...
Dmitry Grigoryev's user avatar
2 votes
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Samsung MZ-76E250B/EU 860 EVO for raspberry pi 4?

Yes, a 860 EVO 500GB works for me at least on Raspbian buster, Pi 4 with this USB 3.0 to SATA adapter https://www.amazon.co.uk/ELUTENG-External-Support-Adapter-Compatible-Black/dp/B06XCV1W97/&qid=...
sackoverflow's user avatar
2 votes
Accepted

Plotting CPU and Ram utilization

egrep is just a shell script that runs grep -E. grep, egrep, and fgrep are a family of commands that share the same binary and man page. Your egrep is probably finding nothing because it is trying to ...
meuh's user avatar
  • 183

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