This depends on the size of the effects and the sample rate. At 48kHz, you can run one of (for example) the following 8 channel presets on each of the two DSPs:

3    23    Octal Compressor

3    16    Compressor_8

3    31    8*10 Grafic Eq

3    12    8 Diatonicshifts

6    20    Combdelays 8ch

6    27    LongPanningDelays8

10  32    4 Stereo Verbs

These are just a few of many – you get the picture …