A: The maximum number of chassis is OS/BIOS-dependent, and depends on the number of PCI Express bus segments in the system. A single device consumes multiple segments (MXI-Express RIO uses four whereas MXI-Express host cards use three). The maximum number of bus segments allowed by the PCI Express spec is 255, although some PC vendors make assumptions in their BIOS to limit the number based on its design assumptions.
Assuming the PC BIOS supports up to 255 bus segments, and that the controller takes about 30 bus numbers for other devices, the maximum recommended configuration is eight daisy-chained lines of six chassis each, for a total of eight MXI adapters and 48 MXI-Express RIO chassis. This configuration should use (48 MXI-Express RIO) * (4 bus segments per MXI-Express RIO) + (8 chassis) * (3 bus segments per MXI-Express host card) + (30 reserved bus numbers) = 246 of the 255 PCI Express bus numbers.