4.4 The Performance Meter

Another useful function provided by NuSystem is the performance meter display.

The N64 hardware includes a unit called the RCP containing the RSP and the RDP, which we mentioned in Chapter 3. These two processors are in charge of audio and graphics processes, freeing the CPU to concentrate on other computational jobs. Graphics tasks are executed by both processors, as described before, while processes relating to audio playback are handled as tasks executed in the RSP.

As you can see, the RCP plays an extremely important role as the unit where graphics and audio tasks are executed. So it would thus be very useful during game development if you can grasp how large a computational load is being placed on the RCP. The NuSystem performance meter shows this load in the form of a simple bar graph.

There are two functions for displaying the performance meter. The two functions differ a little in display content, but both are called using the same syntax.

This displays the type0 performance meter, which displays the RSP's audio tasks and graphics tasks and the RDP's overall processing time.

This function displays the type1 performance meter, which shows more items than the type0 meter.