Can you use multiple 'host' pcs with XPC/Simulink Real-Time

I am trying to produce a sound with frequency dependent on real time outputs from the Target PC using XPC or Simulink Real-time. However, the host pc is trying to run graphics (virtual world) and cannot cope with both graphics and the production of a sound wave. Breaks appear in the sound and the graphics start to freeze. The Target PC is running at too slow a time step for me to produce the desired sound frequencies, so the host needs to produce several points over one time step of the target. Is it possible to network a second 'host' pc into the system so that one can work on graphics and one can work on sound? The PCs I have are a little old, so they may need to be replaced, but adding a second may be easier.

Thanks