When using the RPi and Simulink support package, how fast of a loop rate can we get?

Greetings! As the title says...

I've read some recent journal papers that use an RPi with Simulink for controlling switchmode power supplies, but their details are sparse. As an example, if I used a raspberry pi to control a DC-DC converter, or an MPPT solar charger, how fast can I get my loop rate?

When using a more "traditional" microcontroller or RCP solution, control loop rates of 100kHz are fairly common (I.E. the ADCs are sampled, the algorithm runs, and an output PWM value is yielded every 10 microseconds).