Thanks for your question Matt.
It depends but generally encryption does not work well with deduplication. Deduplication works on the principle of looking for patterns (similar blocks or files) whereas encryption randomizes the data thus eliminating all patterns. If you send encrypted data to a deduplication engine, the deduplication engine will not be able to find any data to deduplicate. The only exception would be if you sent cleartext data to the deduplication engine then encrypted the data at the backend as the deduplication engine writes the data to the disk drives.
The same can be said for data compression as well. Data compression also looks for patterns and optimizes them so encrypted data essentially cannot be compressed.
Roger