64 bit performance tuning tips
Applications that run on the WebSphere Application Server 64-bit version can see significant performance gains if they can leverage the support for large heaps. To exploit the large heap, you can use dynamic cache in WebSphere Application Server. The process to tune dynamic cache remains the same for the 64-bit version as for the 32-bit version. However, all memory references are also 64-bit wide on the 64-bit version, which is twice the size of memory references on the 32-bit version. This size difference causes an increase in the memory requirements of the applications when deployed on 64-bit, as compared to 32-bit.