Hello, I am having an issue with these unboxed arrays. I have some code that creates this structure:: (Array Word16 (UArray Int Word32), Array Word16 (UArray Int Word8)), and I am finding that it uses about twice as much memory as I had anticipated. This tuple is returned strict, and I think I haven't left much room for other data remaining in memory. It should hold one Word8 and one Word32 for a data set of 100 million records, and it uses around 1 gigabyte. By my calculations, it should be half that. So I was wondering if I might have hit upon a 64-bit vs 32-bit issue. I compile with: ghc --make load05 -O1 -funbox-strict-fields -XBangPatterns -fvia-C (also tried with -O2, and without the -fvia-C) using the packaged version of ghc 6.10.1 on MacOSX 10.5.5 Grateful for any pointers, Arne D Halvorsen