While 1 GiB is enough for almost any title, World War Z defies that trend by requiring up to 5.3 GiB of cache to successfully reconstruct its files. This is due to heavy duplication on the game's part since it ships with both a client and server that share large amounts of their files. The resulting heavy deduplication on Epic's part result in lots of cache being required for successful reconstruction. There are basically three ways this could be addressed:

• Optimize file processing order to discard cache sooner (i.e. grouping files that share lots of chunks)
• Throw away cache when it gets full and redownload later (inefficient and would require redownload logic)
• Add on-disk cache to temporarily store excess cache on disk during the download (annoying with mechanical drives)

Since the first two approaches are both complicated and not a cure-all/efficient solution we will have to add on-disk caching capability.