another test: http://exo-blog.blogspot.com/2008/03/windo...done-right.html ".......we were expecting to find little or no performance delta between the two platforms. So we were understandably surprised when repeated test runs showed Windows Server 2008 outperforming Windows Vista w/SP1 by a margin of 11-17%......." another link of neowin http://www.neowin.net/news/main/08/03/12/w...ster-than-vista have fun reading edit: here another link about server and vista http://www.itwire.com/content/view/17140/1103/1/0/ two interesting quoting: "Microsoft has probably already confirmed internally where Windows Server 2008 is indeed faster than Vista SP1. " .........my "Workstation" 2008 experience is that, from a technical standpoint, it doesn't make sense - or at least, it shouldn't. With the same kernel (as of Vista SP1), the OSes should in fact behave similarly.” edited in 3.25.2008: http://exo-blog.blogspot.com/2008/03/windo...done-right.html