System time runs with double speed on systems with ATI RS482 chipset

This document (3932891) is provided subject to the disclaimer at the end of this document.


SUSE Linux Enterprise Server 10
SUSE Linux Enterprise Desktop 10


The system clock runs with double speed on AMD64 and Intel EM64T (AMD64 systems with ATI RS482 chipset)


The kernel parameter noapic needs to be set to the list of kernel boot parameters:

  • For systems using the grub bootloader, addnoapicto the kernel parameter of the default boot section.
  • For systems using lilo, add noapic to theappendparameter of the default image definition and runlilo.

To activate the change, reboot the system.

Additional Information

Some BIOS do not initialize the RS482 chipset correctly. In that case, the chipset delivers the timer tick both through the legacy interrupt controller as well as the APIC (Advanced Programmable Interrupt Controller), which results in two timer interrupts per tick. Specifying the kernel boot parameter noapic disables the APIC. The Linux kernel will then use the legacy interrupt controller instead.


This Support Knowledgebase provides a valuable tool for SUSE customers and parties interested in our products and solutions to acquire information, ideas and learn from one another. Materials are provided for informational, personal or non-commercial use within your organization and are presented "AS IS" WITHOUT WARRANTY OF ANY KIND.

  • Document ID:3932891
  • Creation Date: 01-Dec-2006
  • Modified Date:05-Mar-2021
    • SUSE Linux Enterprise Desktop
    • SUSE Linux Enterprise Server

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