The ostensible performance improvements of a 64-bit compile are a mixed bag in the compressors tested. Those compressors which saw improvement may not even owe that improvement to the 64-bitness of the program, but rather to some other optimization (SSE2, for instance) that is part and parcel of a 64-bit compilation, but not necessarily of a stock Win32 compile.
Here’s a summary of the average change for each compressor.
|Compressor||Avg. Difference (%)|