You talking about this: http://blogs.technet.com/b/perfguru/archive/2008/02/18/explanation-for-the-u sepmtimer-switch-in-the-boot-ini.aspx Webster From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf Of Steve Snyder Subject: [THIN] Re: XenApp 5 - 2008 x64 Slow what CPUs? I had a similar issue with W2K3 x64 and the AMD Opteron - was a boot.ini flag that cured it. Not sure is w2k8 has a similar issue/cure esp. since it uses BCD