Folks, I managed to reduce my memory consumption but I have a performance problem now. This is a profiling report from my app. -O was not supplied when compiling the library and the relevant modules are at http://wagerlabs.com/array.tgz. COST CENTRE MODULE %time %alloc byteArrayFromPtr Script.Array 39.1 43.9 readBits Script.Array 23.6 25.5 emptyByteArray Script.Array 7.6 6.0 endian#2 Script.Endian 4.4 4.2 bytearray Script.Pickle 3.9 3.4 copyMArray Script.Array 2.8 3.4 sequ Script.Pickle 2.7 2.0 withByteArray Script.Array 2.3 2.1 num#2 Script.Pickle 1.3 1.7 wstr#5 Script.Endian 1.1 0.6 byteSize Script.Pickle 1.1 0.5 I run into trouble with packets of ~50K that consist of a header (a few bytes) and compressed data. The compressed data has to be uncompressed and then parsed again. Overall, this takes a copy from array (I use hGetArray) into Ptr Word8 to be supplied to ZLib's compress and then another copy from Ptr Word8 into a byte array for parsing. readBits is supposed to extract numbers from a byte array and can be found in Array.hs. uncompress is in ZLib.hs and the endian bits in Endian.hs. The code should compile without problems. Please help me optimize this! Thanks, Joel -- http://wagerlabs.com/