Might as well ask here, topic title edited within edit window:
Raspberry Pi Compute Module 4 harnesses the compute power of the popular Raspberry Pi 4 Model B
Raspberry Pi Compute Module 5 is a system on module that delivers the power of Raspberry Pi 5
Going with the CM4 because it's expensive in the maxed out config I have. The I/O card is perfect and can be upgraded with the CM5 Compute module. I've got plans to play around with another project or two, the I/O boards are relatively inexpensive and I can play musical chairs with the Compute Module. Knowing myself, the CM6 will be available by date of completion.
I doubt the CM6 will be backward compatible with the CM4 I/O board as it will have a lot of additional pin connections. The CM5 board I wound up with at no cost because I ordered it by mistake and seller didn't want it back. Their admonition to be more careful in the future has been heeded., my bad. Anyway, the CM5 I/O board board is not at all well suited to my needs and the CM6 will likely be a worse fit.
However the additional oomph of a CM5/Raspberry Pi 5 should give me a lot more power for emulation tasks, no? CM4 is a great Linux platform, but a great emulation platform for the PowerBook form factor is the goal here. Might the CM5 upgrade give me the capability of running significantly higher OS level emulation?