SUPER MICRO Computer X8STI-LN4 QPI Frequency, QPI L0s and L1, Memory Frequency, Memory Mode

Chapter 4: AMI BIOS

QPI Frequency

Use this option to set the QPI frequency. The options are Auto, 4.800 GT, 5.866 GT, and 6.400 GT.

QPI L0s and L1

Select Enabled to lower the QPI power state. L0s and L1 are automatically selected by the motherboard. The options are Disabled and Enabled.

Memory Frequency

Use this option to force the system memory to run at a different frequency than the default frequency. The available options are Auto, Force DDR-800, Force DDR- 1066, and Force DDR-1333.

Memory Mode

The options are Independent, Channel Mirror, Lockstep and Sparing.

Independent - All DIMMs are available to the operating system.

Channel Mirror - The motherboard maintains two identical copies of all data in memory for redundancy.

Lockstep - The motherboard uses two areas of memory to run the same set of operations in parallel.

Sparing - A preset threshold of correctable errors is used to trigger fail-over. The spare memory is put online and used as active memory in place of the failed memory.

Demand Scrubbing

Demand Scrubbing is a process that allows the CPU to correct correctable memory errors found on a memory module. When the CPU or I/O issues a demand-read command, and the read data from memory turns out to be a correctable error, the error is corrected and sent to the requestor (the original source). Memory is updated as well. Select Enabled to use Demand Scrubbing for ECC memory correction. The options are Enabled and Disabled.

Patrol Scrubbing

Patrol Scrubbing is a process that allows the CPU to correct correctable memory errors detected on a memory module and send the correction to the requestor (the original source). When this item is set to Enabled, the North Bridge will read and write back one cache line every 16K cycles, if there is no delay caused by internal processing. By using this method, roughly 64 GB of memory behind the North Bridge will be scrubbed every day. The options are Enabled and Disabled.

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