The Choices... dialogue
The choices dialogue has a set of action buttons at the bottom of the window.

The actions available are:
- Set
- This will use the new settings with immediate effect, and they will be used until CPUClock is quit.
- Save
- This will use the new settings, as in Set above, and will also save the settings to disc, so they will be used when CPUClock is run in the future.
- Cancel
- Close the dialogue and ignore any changes made since it was opened.
At the top of the window are three tabs, labelled Application, Module and Statistics. The first two sections control the application and module specific settings, the third tab settings apply to both the module and the front end.

Application
The application tab is shown below.

- Poll idle delay/cs
- CPUClock checks the current speed of the cpu periodically, and writes the value under the iconbar icon, and in to the status window if it is open. The delay between checks can be adjusted using the bump arrors at the right. The value is in centiseconds. The default delay is 100cs (1s). Long delays may miss short bursts of cpu activity, while short delays may actually load the cpu. The temperatures of the cpu and the case (if applicable) are updated at the same time.
- Iconbar icon at right
- When an application installs an icon on the iconbar, by default it is installed at the left end of the right hand side icons. Thus the position is variable. If you wish to keep an eye on the cpu speed, it might be useful to have the iconbar icon in a relatively constant position. If this is ticked, then the iconbar icon will be installed to the right of the normal application icons (some applications have a high priority for positioning, e.g. the task or display managers, and CPUClock does not install to the right of these). Note that CPUClock will need to be quit and restarted before the change will take place. You will be offered the option of restarting immediately, or waiting.
- Iconbar icon text shows
- It is now possible to choose whether to show either the continuously updated CPU clock speed or the updated CPU die temperature below the iconbar icon. The two radio buttons CPU speed and Temperature allows you to switch between the two displays.
- Open status on launch
- If this is ticked, then CPUClock will open the status window whenever it is first loaded. The position at which it will be opened can be set by moving the status window to the position of your choice, then ticking the option Save position now. If choices are now saved, the current position of the status window will be saved as well. The requirement to tick this option means that the setting is not changed when choices are saved at other times, unless a new position is specifically set. Note that the status window will always be opened at the smaller size.
The CPUClock iconbar icon always gives an indication of the CPU speed and temperature. By default, it shows the CPU clock speed as it changes with cpu load. This can be changed to show the CPU temperature instead. CPUClock can also give a colour coded indication of the cpu temperature status. The next section controls what form this indication takes.
- Show colour-coded status
- This turns the colour coding on. The colour is shown either as a
background to the text under the iconbar icon or as a background to the
whole icon. This is set by the two radio icons, Text background
and Whole icon. A further option Show low temperature as
green toggles between a green background or no background for the low
temperature condition. Examples are shown below.
Appearance when Text background is set Appearance when Whole icon is set 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.
Module
The module settings are used to control the operation of the CPUClock module.
The Module tab is shown below.

At the top is an option to set the interval between each read of the cpu temperature. This is quite separate from the poll-idle setting in the GUI front end. The read interval is in units of centiseconds and values between 40 and 300 cs are allowed. The default is 75 cs.
The lower section controls how auto temperature control is set up.
- Enable auto control
- If this option is ticked then CPUClock will enable the cpu temperature regulation in the CPUClock module. The module will reduce the fast speed setting if the temperature exceeds the set maximum value. If it is unticked the module will simply read the cpu temperature (and collect the temperature statistics) but do no cpu speed reduction whatever the cpu temperature rises to.
If the auto speed control is enabled, then the following settings will influence how the control will be actioned
- Maximum temperature/°C
- This value (in °C) sets the maximum cpu temperature that is allowed before the cpu speed will be reduced. The maximum working temperature for a particular cpu will be found in the reference manual for the board. However, as a rough guide, 65°C to 70°C is probably a suitable upper limit. 60° would be even safer for long term use.
- Differential/°C
- This value (in °C) sets the number of degrees by which the temperature must fall below the maximum setting before the cpu speed will be increased again. A setting of 3 or 4°C is usually suitable.
- Use rolling average temperature
- If the temperature of the cpu die is close to the maximum temperature setting, the short term fluctuations (always present) may trigger the regulation. If this is felt to be a problem, the module can be set to keep a running average of the last four temperature readings. This smooths out the temperature fluctuations to some extent, but at the same time the regulation operation will be slower. The default setting is for there not to be any averaging.
Statistics
The statistics settings are used to control how the CPUClock module and front end deal with producing and using the temperature statistics.
The Statistics tab is shown below.

- Enable statistics production
- If this option is ticked, then the module will collect the statistics for temperature variation. The GUI front end will allow the collected data to be saved to file for subsequent viewing or analysis.
- Stats accumulation time
- This allows the setting of the time slot (in seconds) over which
the the cpu maximum and minimum temperatures are determined. This can
be varied in the range 5 to 60 seconds. The maximum and minimum
temperatures in each period will be recorded. These values will be
mirrored by the values shown in the status window.
This setting does not effect the collection of raw data. The raw temperature data is collected each time the temperature is read - this time is set in the Module tab, described above.
- Statistics file format
- This section is used to set the file format of the data file.
Currently, there are three formats.
- CSV is a simple comma separated format, which can be loaded in to various spreadsheet type applications
- MultiPlot format allows the data to be loaded into the author's !MultiPlot application
- ChartDraw format allows the data to be loaded into the author's !ChartDraw application
Both applications !ChartDraw and !MultiPlot can be obtained from the author's web site (see the Contact page) or via !Store or !Packman.
The image below shows an example of a set of raw data obtained over a period of about an hour on Titanium hardware and displayed in !ChartDraw.

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CPU temperatures of 48-52 occur when the cpu is essentially idling. The temperatures in the mid 50s were attained during editing and viewing of html pages. The temperatures in the low 60s occurred during the few minutes spent batch processing a couple of dozen DSLR jpeg images.
The final option buttons define how the data files are saved, and should require little further explanation. If Save as separate files is ticked, then each of the three sets of data are saved as separate files. If unticked, then if more than one data set is selected to be saved, the combined data is included in a single file. The other three options determine which data sets are saved. The data files are stored in the directory Stats within the application. The iconbar menu has an option to open a filer window on this directory for quick access.