The icon turns red when the temperature reaches a certain threshold. The application is designed to be simple and easy to use. The CPU and memory consumption are not significant.
It can monitor:
-the temperature of the motherboard and CPU sensors (using lm-sensors).
-the temperature of the NVidia GPUs (using XNVCtrl).
-the temperature of ATI/AMD GPUs (not enabled in Ubuntu PPAs or official distribution repositories, see the instructions for enabling its support).
-the temperature of the Hard Disk Drives (using hddtemp or libatasmart).
-the rotation speed of the fans (using lm-sensors).
-the CPU usage (since 0.6.2.10 and using Gtop2).
Psensors makes use of lm-sensors and hddtemp to get the temperatures, so you need to install these two packages:
sudo apt-get install lm-sensors hddtemp
To get the hddtemp daemon to run on boot, use the following command and select "Yes" when asked if hddtemp should run at boot. Select the defaults for the other questions.:
sudo dpkg-reconfigure hddtemp
Next, you need to set up lm-sensors by running the following command and answer "yes" to everything.:
To avoid a system restart, run the following command to load the modules required by the sensors (if no sensors show up in Pensor, try a system restart):
sudo add-apt-repository ppa:jfi/ppa
sudo apt-get update
sudo apt-get install psensor
By default, the latest Psensor doesn't start automatically when you login (unless you've upgraded from an older version). If you do want it to run on startup, in its Preferences (not Sensor Preferences!), click on the Startup tab and then enable "Launch on session startup". If you don't want the Psensor window to be displayed on startup (for instance, you only want the indicator to start automatically - you can manually open the Psensor window later on), also enable "Hide window on startup".