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System Type
The type of system Centrych will be installed on determines which of the options in the three lower panels are enabled and also presets the options below to a suggested configuration for that system type.

This system type defaults to the CFQ I/O scheduler, no dynamic ticks, and a tick rate of 1000Hz.
This system type has the same settings as the desktop system type except for dynamic ticks, which is selected by default.
Virtual Machine
This system type is quite different from the desktop and laptop system types. It deselects the PAE kernel option, selects the deadline I/O scheduler, enables dynamic ticks, and sets the tick rate to 250Hz.
Note: the virtual machine system type also changes the settings of several options on the next panel.

Note: the initial system type selected is based on internal checks performed prior to opening this panel the first time.

Kernel type
There are two types of optimized kernels to choose from due to a limitation in the Linux kernel that only allows for one process scheduler, which has to be compiled into the kernel. For i386 machines each optimized kernel comes in the non-PAE and PAE versions.

BFS scheduler
The BFS scheduler is designed for desktop use and provides a more interactive and responsive experience when compared to the default CFS scheduler.

    • This scheduler is considered experimental. Please review the issues page if you plan to use this scheduler in a VMware virtual machine (guest)
    • When the BFS scheduler is selected the BFQ I/O scheduler will also be selected if the system type is not set for virtual machine
    • When the BFS scheduler is unselected the CFQ I/O scheduler will also be selected if the system type is not set for virtual machine
    • When the system type is set for virtual machine the deadline I/O scheduler will be selected, regardless of the setting of BFS
PAE kernel
This item is only enabled on i386 systems with a CPU that supports the PAE capability. It will default to checked if the system has 3GB or more memory available. The one exception is when selecting a virtual machine system type, it defaults to unselected in that case.

I/O Scheduler
The BFQ scheduler is available in all optimized kernels. The others are the default schedulers that come with the Linux kernel.

Note: this scheduler is considered experimental. Please review the issues page for a discussion on potential lockups when using this scheduler with a VMware host machine.

Kernel options
There are currently two options available for tuning kernels under certain situations.

Use dynamic ticks
It is recommended to enable this option when using a laptop to reduce power consumption and in a virtual machine to reduce idle CPU utilization.
Tick rate
The default rate in the optimized kernels is 1000Hz. For virtual machines it is suggested to lower this to 250Hz.
Note: faster tick rates improve interactive response at the expense of CPU throughput, the opposite is true with slower tick rates.

Please refer to the kernel page for additional information.

Note: the live DVD document for this page contains links to the following additional pages that have not been included here:
  • Issues
  • Kernel