Raspberry pi best heatsink comparison benchmark


Raspberry Pi manufacturer have stated you don’t need heatsink for the normal operation of the Raspberry Pi device, however overclocked or heavily stressed devices will benefit from heatsink installation.
I decided to compare available heatsinks on the market and have found the best heatsink for Raspberry Pi 3.

First tested heatsink is small – 14x14x6mm, priced 1$ on Ebay
It has an adhesive layer for mounting on CPU.


Second heatsink – is larger 50x25x10mm, also priced 1$


Mounting was done with Arctic Silver thermal compound and и super-glue 🙂 Thermal compound was applied to the center and glue – to the corners of the chip.
Please note that this will be a permanent solution, and you will not be able to remove the heatsink.

For loading the CPU I used stress software (apt-get install stress).
Only 1 core of Raspberry Pi 3 was loaded – frequencies: arm_freq=1290 core_freq=430

Here are the temperature graphs:


Red line – no heatsink.
Blue – small heatsink 14х14
Gren – large heatsink 50х25

For a price of 1$ you can greatly improve temperature of Raspberry Pi 3 – by 8 degrees in idle state and by 13 degrees under moderate load.

Remove all store apps windows 10


If you don’t use new (modern / metro) style application in windows you can delete all of them with a single PowerShell command.
To open PowerShell: Right click on Windows logo -> Command Prompt (Administrator – type powershell and press Enter.

This command removes all store apps for currently logged in user.

Get-AppxPackage | Remove-AppxPackage

To delete installation packages from disk and prevent installation for new users:
WARNING! This cannot be undone, you will lose ability to install new apps from Windows Store.

Get-AppXProvisionedPackage -Online | Remove-AppxProvisionedPackage -Online

Automating tasks with cron on CheckPoint Gaia

To use cron on CheckPoint Gaia firewall you need to create a separate user, as “admin” user crontab file is overwritten on every reboot by /bin/cron_xlate.

Instead of using default command :
> crontab -e
It will warn you as follows:

#  Generated by /bin/cron_xlate on Wed Jan 14 13:33:33 2015
# mins  hrs     daysinm months  daysinw command

You will also need to specify the user:

> crontab -u cron_user -e

To create a new user for cron, use following commands:

add user cron_user uid 0 homedir /home/cron_user
set user cron_user  gid 100 shell /bin/bash
add rba user cron_user roles adminRole
set user cron_user password <ENTER>

Make sure you use new user’s home folder for output in your scripts, to avoid issues with permissions.

SSHd server not starting at boot RHEL / CentOS 7

By default sshd server does not start in CentOS 7.
chkconfig command does not control ssh daemon any more.

Solution is to use systemctl:

> systemctl enable sshd

It produces following awkward result:
ln -s ‘/usr/lib/systemd/system/sshd.service’ ‘/etc/systemd/system/multi-user.target.wants/sshd.service’

To check if SSH server is staring on boot (and if it is running):

> systemctl status sshd

sshd.service - OpenSSH server daemon
   Loaded: loaded (/usr/lib/systemd/system/sshd.service; <strong>enabled</strong>)
   Active: active (running) since Mon 2014-11-03 18:43:56 GMT; 20min ago

Enabled – means it will start at boot time automatically.
Welcome to systemd world..