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Once the RAID volumes have been created and a file system created on a RAID volume, there is one last setting which can dramatically improve performance on the volume: disabling the file system write buffer flushing. This setting controls whether Windows aggressively tries to keep file system related information synchronized between what is stored in the relatively fast RAM and what is stored in the relatively slower permanent storage system. To keep the data between the two in sync, the data in RAM needs to be written out to the RAID system as often as possible in case there is a sudden and unexpected loss of power. In the case of sudden power loss, any information that was kept in RAM but not committed to the permanent storage system (i.e. the RAID drives) will be lost forever. However, this strategy to protect against potential data loss comes at the price of performance when the system is under heavy loads. But sometimes it is the cache buffer flushing which is actually contributing to the heavy system workloads. This means that one of the of the performance improving options for systems with heavy workloads is to disable this aggressive cache flushing behavior.
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