Background | Installation | Basic operation | The iconbar menu | The choices window | The status window | Contact | Versions | Module details | Licence
Background | Installation | Basic operation | The iconbar menu | The choices window | The status window | Contact | Versions | Module details | Licence
Important: CPUClock is only of use on modern hardware that is capable of switching the CPU between two or more speed settings. This means hardware such as the OMAP3, OMAP4, or OMAP5.
When run, CPUClock, the GUI frontend and/or the module, makes some checks on the OS and hardware. If the hardware is unsuitable, CPUClock will not run. If the OS is an old version, then CPUClock may run, but some of the functionality may be disabled.
The following description uses extracts from a post by Jeffrey Lee in the ROOL forum (with permission).
RISC OS does several things to control the speed of the CPU:
For a new installation, simply drag and drop the CPUClock application into the directory of your choice.
If you have a previous copy of CPUClock you should move the old version of CPUClock somewhere safe and replace it with the new version.
Version 2 of CPUClock operates in the following way.
To run the application, double click on it's icon in a filer window. This will load the GUI front end onto the iconbar. It will also load the CPUClock module (if not already active). It is this module that monitors the cpu temperature, and adjusts the cpu clock speed if necessary. A module is used for this since it remains active even if the wimp enters a single-tasking state when e.g. a task stops polling during a processor intensive operation.
The iconbar icon will show the cpu clock speed as the OS switches between fast and slow, as shown below for a PandaBoard-ES. There is also a user option to include a coloured status indication of the cpu temperature in the iconbar icon. See the description of options in choices below.
Clicking on the iconbar icon with Select (or using the iconbar menu) will open the status window, which will show the cpu speed, the temperature, and will allow changing the fast (and slow) speed setting, although there is little to be gained by increasing the slow speed. More details are given below.
CPU speed only operation
If CPUClock finds the OS does not support all the functions required for measurement of temperature and auto-control of cpu temperature and clock speed, then it may revert to simply displaying the cpu clock speed (see below). In this case it may be more useful to revert to using version 1.10 of CPUClock instead. See the page on versions.
A screen shot of the iconbar menu is shown
right.
Info – A standard application info box, including a button to go to the web site to check for later versions.
Help... – Runs the help file (this one).
Module info – Following this option right brings up a small window showing the current setup of the CPUClock module. This should correspond to the choices settings in the CPUClock frontend, if nothing else has changed the settings.
Status... – Opens the CPU clock speed status window (see below). Clicking on the iconbar icon with Select will also open the CPU status window.
Choices... – This opens the application choices window (see below). The choices window can also be opened by a right click on the iconbar icon.
Quit – This terminates the frontend application immediately, but leaves the module active. In addition, following the submenu arrow right leads to a menu with two options. Frontend only will terminate the GUI application. Selecting Module also will terminate the frontend and RMKill the module. Terminating just the GUI frontend means that the module will remain active and continue to operate in the background, monitoring the cpu die temperature, and reducing the cpu clock speed if the temperature exceeds the set value.
The choices dialogue has a set of action buttons at the bottom of the window.
The actions available are:
At the top of the window are two tabs, labelled Application and Module. The two sections control the application and module specific settings.
The application tab is shown below.
The CPUClock iconbar icon, by default, shows the cpu clock speed as it changes with cpu load. CPUClock can also give a colour coded indication of the cpu temperature status. The next section controls what form this indication takes.
Appearance when Text background is set | |||
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Appearance when Whole icon is set | |||
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From the left (1) Cpu at low temperature when Show as green is off. This is also the form of the icon at any cpu temperature when Show colour-coded status is off. (2) Cpu at low temperature and Show as green is on. (3) Cpu at temperature between upper and lower limits (4) Cpu temperature above upper limit. |
The module settings are concerned with how the CPUClock frontend interacts with the CPUClock module.
The Module tab is shown below.
If the auto speed control is enabled, then the following settings will influence how the control will be actioned
Clicking SELECT on the oconbar icon (or using the iconbar menu) will open the Status window. This may take two forms. The default window shows the cpu clock speed and the cpu die temperature, as shown below.
However, it is possible that the board is fitted with the CJE RTC module with temperature sensor. This sensor measures the temperature close to the board, which will be a function of the ambient case temperature. Assuming CPUClock has detected the presence of the board, an additional field showing the ambient case temperature will be present, as shown below. CJE products such as the PandaRO or RapidO Ig are so fitted. The boards can also be user fitted to a PandaBoard-ES for example.
The display will show the current cpu clock speed (switching between the 'fast' and 'slow' speeds depending upon how hard the CPU is working), the cpu die temperature, and the ambient case temperature if the board is fitted with a sensor. The small coloured icon to the right of the cpu temperature changes from green to orange to red as the cpu temperature approaches and then exceeds the set temperature limit (see Choices).
Note that the CPUClock front end updates the values, by default, every 1 second using wimp NULL poll-idle events. See Choices (above). If the wimp is not multitasking at that instant, e.g. processing an image, then the display cannot be updated. However, in general use you should see the speed being switched between 'fast' and 'slow' as you do things in the desktop. Note that the module will continue to get the temperature and do any auto-controlling required in the background, even if the front end is not being updated.
Clicking on the 'maximise' icon at the top right of the status window title bar will extend it, with two additional fields, showing the configured settings for the 'fast' and 'slow' speeds.
Clicking on the popup menu button to the right of the 'Fast' or 'Slow' fields will raise a menu listing the allowable CPU clock speeds. Selecting one of these speeds will reset the 'Fast' or 'Slow' setting as appropriate to this new value. This is a 'permanent' setting in the sense that it will remain in force until either specifically changed again, or the machine is rebooted.
Reducing the 'Fast' speed may be beneficial in high ambient temperature conditions. It is unlikely there will be any benefit in raising the 'Slow' speed, since this is used when the processor is idling.
If CPUClock is running in cpu speed only mode, then a much simpler status window is used. This contains a field to display the current cpu speed, and the two popup menu buttons and associated display fields to set the fast (and slow) cpu speeds. The window is shown below.
All communication about the CPUClock frontend and the CPUClock module should be directed to Chris Johnson (Email:chris@chris-johnson.org.uk). Suggestions for new features are always welcome.
Chris Johnson's web site is at http://www.chris-johnson.org.uk/index.html, with his RISC OS software at http://www.chris-johnson.org.uk/software/index.html.
All the screen shots in these pages were obtained using Snapper, a versatile screen capture application.
Snapper is available from http://www.chris-johnson.org.uk/software/snap.html
CPUClock is © Chris Johnson, 2012
Email:chris@chris-johnson.org.uk
Document last modified on 6th April, 2016