Even though blocking is not required for train operation with DCC, sectioning the layout has two advantages:
1. To provide additional power to operate more locomotives than one power supply can handle.
For example a 4 Amp booster and power supply will operate between 6 and 10 average N-scale locomotives, between 4 and 6 HO locomotives and 2 to 4 G scale locomotives. You can run more equipment by sectioning the layout and adding additional boosters and power supplies.
For large-scale operations you can use higher current boosters to deliver more power to individual sections if needed to run more trains.
A note about boosters and current ratings: most DCC boosters will require an external fan in order to output the stated maximum current for extended periods of time. This is not an issue for most modelers but if you experience booster shutdown, you should consider adding fans to increase heat-sinking capability.
2. To prevent total layout shutdown when shorts occur in any given section.
If a short occurs in one section, only that section shuts down, the rest of the layout keeps operating. The reason for this is that all of the boosters are linked to the command station and will continue to receive the DCC signal and output it to their own section of track.
You can avoid purchasing additional boosters and still section your layout by using DCC Specialties PSX DCC Circuit Breakers and Reversers.