VirtualRPC-SA User Guide

Power Saving


VirtualRPC-SA now includes a power saving component in the plugins folder as part of the HostServices plugin. This is designed to extend battery life on portable devices. Early versions of VirtualRPC-SA ran the processor at full speed all the time. Using power saving the CPU can be throttled down when RISC OS does not need full performance. The power saving component is activated by a the VAPower configure plug-in. By default Power Management is on, to turn it off double click on !Boot to open the configure application and click on VAPower. If you are running on a desktop machine that does not require power management then you can leave power management disabled.


VAPower configuration

Battery Manager

VirtualRPC-SA includes a battery manager that can be installed on the iconbar using the VAPower configuration plugin. You will need to reboot for the battery manager to be loaded. Once loaded you will see a battery icon on the iconbar to the left of the Display icon. By default this will show a drawing of a battery along with the current power level in percent (100% is a fully charged battery). Pressing SELECT over this icon will open a Portable power status window. This will show the current charge state, battery level and, if your hardware supports it, the remaining battery time. There are also two tick boxes that allow the battery manager to warn you when the battery level drops below 25% and again when it drops below 10%.


Battery manager

The battery manager has three different display modes.

You can cycle through these three options by clicking ADJUST on the battery manager icon on the icon bar. You can also save your preferred icon as well as the status of the two power warnings by clicking on the OK button in the Portable power status window.

RISC OS performance with power saving

Power saving should not have any effect on RISC OS performance, however when running VirtualRPC-SA in a window you may find that the MIPS rating drops to very low figures, this is because RISC OS does not require all the processor time, if you try loading a file or doing some screen redrawing you will find the MIPS figure goes up again as RISC OS demands more processor power. On most laptops using power saving you should find that the fan only comes on when RISC OS is involved in processor intensive calculations. This will extend the battery life.

Using RISC OS Select with power saving

RISC OS Select requires an updated version of the TaskManager module for power saving to function properly. A copy of this can be found in the SelectSupport directory inside the VirtualRPC-SA HardDisc 4. If this new module is not installed then RISC OS will freeze when trying to shutdown. To install this simply drag the copy of !Boot from the SelectSupport directory and drop it over your existing !Boot in the root of HardDisc4. Now quit and re-load VirtualRPC-SA.

VRPC manual - draft number 150.001 10th May 2006