Archiving data that is ready to be archived will help you get results faster. It’s one of those things that improves every aspect of the database engine.
- Less data to look at on storage.
- Less data to bring into memory.
- Less data to run a calculation on for CPU.
- Less data to send over the network to the client.
- Less data to keep stats on for plans.
Every resource SQL Server relies on for generating a result set is improved when there’s less data to evaluate. The hard part is that “ready to be archived” bit, but it can make such a large impact that you should think about archiving long before you need it.