id summary reporter owner description type status component version resolution keywords cc guest host 3613 High CPU usage with idling guest induced by RTC interrupts Nerijus "Bug possibly related to: #1884 Occurs on both Vbox 2.1.4 and 2.2.0 Beta2 With Windows 7 guest, and possibly Windows Vista, Windows XP SP3, Windows Server 2008, Windows Server 2008 R2 guests. When running: - MS SQL server 2008 (express or not), - SQL server 2005 SP3 - TwinCat - Google Chrome - Or possibly another application which uses 70h interrupts for timing virtual box uses ~60-70% of single CPU, while guest OS is almost idle. What was expected to happen: Host should be almost idle too. Upon further investigation, it appears that these programs use ""Real-Time Clock Interrupt"", which fires 1024 times per second. Source: http://blogs.msdn.com/psssql/archive/2008/12/16/how-it-works-sql-server-no-longer-uses-rdtsc-for-timings-in-sql-2008-and-sql-2005-service-pack-3-sp3.aspx Problem with SQL server 2008: Forum thread: http://forums.virtualbox.org/viewtopic.php?f=2&t=15668 Same thing happens with Google Chrome. Bug ticket: http://www.virtualbox.org/ticket/1884 TwinCat Forum thread: http://forums.virtualbox.org/viewtopic.php?f=2&t=12941 How problem can be observed with Windows 7 guest (and possibly other guests): 1. Open ""perfmon"", and add ""Processor->Interupts/sec"" counter to monitor. 2. Start Google Chrome (or another mentioned application), and wait for it to finish initialization. 3. Watch interrupt count to increase by 1024 per second. This is expected. Guest remains idle. 4. However, on host, CPU usage increase significantly." defect closed VMM/RAW VirtualBox 2.1.4 obsolete Windows other