Hi Thomas and Peter, hi everyone, Asynchrounous events (e.g.SMIs) which occur during the APIC timer calibration can cause timer miscalibrations, sometimes by large amounts. This patch fixes this by two separate measures: a) make sure that no significant interruption occurs between APIC and TSC reads b) make sure that the measurement loop isn't significantly longer than originally intended. I am sorry, due to a misconfiguration of our SMTP server I need to send the patch as attachment. Martin -- Martin Wilck PRIMERGY System Software Engineer FSC IP ESP DEV 6 Fujitsu Siemens Computers GmbH Heinz-Nixdorf-Ring 1 33106 Paderborn Germany Tel: ++49 5251 8 15113 Fax: ++49 5251 8 20209 Email: mailto:martin.wilck@fujitsu-siemens.com Internet: http://www.fujitsu-siemens.com Company Details: http://www.fujitsu-siemens.com/imprint.html