Hi, In an application I'm writing with Data.Binary I'm seeing very fast write performance (instant), but much slower read performance. Can you advise where I might be going wrong? The data type I'm serialising is roughly: Map String [Either (String,[String]) [(String,Int)]] A lot of the String's are likely to be identical, and the end file size is 1Mb. Time taken with ghc -O2 is 0.4 seconds. Various questions/thoughts I've had: 1) Is reading a lot slower than writing by necessity? 2) The storage for String seems to be raw strings, which is nice. Would I get a substantial speedup by moving to bytestrings instead of strings? If I hashed the strings and stored common ones in a hash table is it likely to be a big win? 3) How long might you expect 1Mb to take to read? Thanks for the library, its miles faster than the Read/Show I was using before - but I'm still hoping that reading 1Mb of data can be instant :-) Thanks Neil