warning: many lost ticks
Problem
The kernel reports the following error mesages:
Losing some ticks... checking if CPU frequency changed. warning: many lost ticks. Your time source seems to be instable or some driver is hogging interupts
Solution
To facilitate power management, the BIOS periodically adjust the speed of all the fans (CPU and chassis) depending on the system temperature. But the process uses up clock ticks causing the OS to report the "Warning: many lost ticks" messages. To avoid the lost ticks while running Linux, the fan control mode must be disabled in the BIOS (default setting at the factory).
The 2nd source for the lost ticks occurs on the nForce SATA controllers. The Marquis K828 has two SATA chips residing on the nForce Pro 2200 (CK804) and nForce Pro 2050 (CKI04) chipsets. Each SATA chip consists of two discrete 2-port SATA controllers. This provides a total of eight SATA ports as shown below:
CK804
| Controller | First port | Second port |
|---|---|---|
| SATA #1 | 0 (1) | 1 (2) |
| SATA #2 | 2 (3) | 3 (4) |
CKI04
| Controller | First port | Second port |
|---|---|---|
| SATA #1 | 0 (5) | 1 (6) |
| SATA #2 | 2 (7) | 3 (8) |
When running both ports simultaneously on any SATA controller, lost tick will occur under heavy disk activity. To avoid the lost tick, only connect one hard drive per SATA controller. This issue affects all nForce4 and nForce Pro motherboards.
A system configured with 4 hard drives will have the following connection:
- 1st disk => CK804 SATA #1 controller, Port 2
- 2nd disk => CK804 SATA #2 controller, Port 0
- 3rd disk => CKI04 SATA #1 controller, Port 2
- 4th disk => CKI04 SATA #2 controller, Port 0
A system configured with 3 hard drives will have the following connection:
- 1st disk => CK804 SATA #1 controller, Port 2
- 2nd disk => CK804 SATA #2 controller, Port 0
- 3rd disk => CKI04 SATA #1 controller, Port 2
A system configured with 2 hard drives will have the following connection:
- 1st disk => CK804 SATA #1 controller, Port 2
- 2nd disk => CK804 SATA #2 controller, Port 0
A system configured with 1 hard drive will have the following connection:
- 1st disk => CK804 SATA #1 controller, Port 2
Even though the motherboard supports eight SATA disks, never use more than four disks.
The 3rd source for the lost tick occurs on the nForce Gigabit Ethernet controllers. These Ethernet ports can be accessed using the open source driver (forcedeth) or Nvidia supplied driver (nvnet). When using forcedeth, the driver version must be 0.47 or higher.
Because Red Hat Enterprise Linux 4 includes an out of dated driver (v 0.30), always use the ASL RHEL4 Device Driver CD when installing the operating system. This CD contains an updated forcedeth driver. To download the latest ASL RHEL4 Device Driver CD, visit ASL online FAQ.
In summary, lost ticks can be avoided when applying all three rules below: