The Custom LZMA Settings Page

Compression Settings

Dictionary size

Specifies dictionary size for compression. Usually higher dictionary size gives more compression ratio, but compressing can be slower and it can require more memory. Memory (RAM) usage for LZMA compressing is about 11 times more than dictionary size. Memory usage for LZMA decompressing is close to value of dictionary size.

Word size

Specifies the length of words, which will be used to find identical sequences of bytes for compression. Usually for LZMA big word size gives a little bit better compression ratio, but a slower compression process. Big word size parameter can significantly increase compression ratio in case when files contain long identical sequences of bytes.