WiX provides two ways of speeding up the creation of cabinets for compressing files:
Light uses multiple threads to build multiple cabinets in a single package. Unfortunately, because the CAB API itself isn't multithreaded, a single cabinet is built with one thread. Light uses multiple threads when there are multiple cabinets, so each cabinet is built on one thread.
By default, Light uses the number of processors/cores in the system as the number of threads to use when creating cabinets. You can override the default using Light's -ct switch or the CabinetCreationThreadCount property in a .wixproj project.
You can use multiple cabinets both externally and embedded in the .msi package (using the Media/@EmbedCab attribute).
If you build setups with files that don't change often, you can generate cabinets for those files once, then reuse them without spending the CPU time to re-build and re-compress them.
There are two Light.exe switches involved in cabinet reuse:
WiX automatically validates that a cached cabinet is still valid by ensuring that: