From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Venefax" Subject: RE: Windows SMP Date: Sun, 28 Dec 2008 21:59:44 -0500 Message-ID: <03e901c96961$81b81980$85284c80$@com> References: <036501c96898$959aaef0$c0d00cd0$@com> <03e401c9695f$f7ebb8c0$e7c32a40$@com> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-us List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: 'James Harper' , 'Dirk Utterback' Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org I had to disable both, and PAE. Only APIC=0 would not make any difference. I will some further testing with Citrix Xenserver 5, using the same virtual machine and another copy with their vmpd drivers. I bet that there is no difference in performance. It seems to be a Xen architectural issue. Any ideas? -----Original Message----- From: James Harper [mailto:james.harper@bendigoit.com.au] Sent: Sunday, December 28, 2008 9:53 PM To: Venefax; Dirk Utterback Cc: xen-devel@lists.xensource.com Subject: RE: [Xen-devel] Windows SMP > > The problem is not SMP, is ACPI. I installed a non-ACPI Hal, but SMP > capable, and the performance went right up with 4 virtual processors. > > I hope the developers can look into this mess. > Can you have ACPI enabled but APIC disabled, or is that not a valid configuration? Or the other way around, can you have ACPI disabled but APIC enabled? Maybe the APIC emulation is causing a performance loss? James