more ram always helps, some programs cam be resource hogs, and the extra ram can make a decent difference. i changed my small iede drive to a terabyte sata drive, the improved throughput sped things up a bit, switching from 32 bit to 64 bit helps too, again due to increased throughput, ram is cheaper, but for an improvement you need a kit: 4 GB to 8 GB RAM. Where's the performance increase? - Windows 7 Forums
Generally speaking, yes, it definitely has the potential to yield a significant performance gain. However, Joe is absolutely correct. You must be using a 64-bit OS to take advantage of 8Gb. And before migrating to 64-bit, you must ensure 64-bit drivers are available for all your hardware.