WRITE_CACHE_TYPE enumeration (ntddstor.h)

The WRITE_CACHE_TYPE enumeration specifies the cache type.

Syntax

typedef enum _WRITE_CACHE_TYPE {
  WriteCacheTypeUnknown,
  WriteCacheTypeNone,
  WriteCacheTypeWriteBack,
  WriteCacheTypeWriteThrough
} WRITE_CACHE_TYPE;

Constants

WriteCacheTypeUnknown The system cannot report the type of the write cache.
WriteCacheTypeNone The system cannot report the type of the write cache.
WriteCacheTypeWriteBack The device has a write back cache.
WriteCacheTypeWriteThrough The device has a write through cache.

Remarks

There are two main types of write cache: write back and write through. With a write-back cache, the device does not copy cache data to nonvolatile media until absolutely necessary. This type of operation improves the performance of write operations. With a write-through cache, the device writes data to the cache and the media in parallel. This type of operation does not improve write performance, but it makes subsequent read operations faster.

The IOCTL_STORAGE_QUERY_PROPERTY request reports a WRITE_CACHE_TYPE value in the STORAGE_WRITE_CACHE_PROPERTY structure.

Requirements

Requirement	Value
Header	ntddstor.h

See also

IOCTL_STORAGE_QUERY_PROPERTY

STORAGE_WRITE_CACHE_PROPERTY