I was looking through HP's faq for their HP-UX11 64bit OS, and I noticed something that surprised me. That is, running a 64bit application in the 64bit OS results in an 8-9% performance hit as compared to a 32bit app in a 32bit OS. Would this apply for other 64bit apps/OS as well? I understand that using 64bit gives you access to a boatload of memory compared to 32bit, so would you make up for the performance hit by utilizing more memory to run your app? Any additional comments about 32bit vs 64bit would be appreciated.