Western Digital Technologies, Inc.

Sandisk Technologies Inc.

Guruswamy Ganesh

Shay Benisty

Ariel Navon

Dinesh Kumar Agarwal

Yair Baram

Hitesh Golechchha

A storage system and method are provided for hit-rate-score-based selective prediction of future random read commands. In one embodiment, a storage system is provided comprising a memory configured to store a prior read command data structure, the prior read command data structure comprising a hit-rate score field. The storage system receives a current read command; generates a search sequence of read commands comprising the current read command and at least one prior read command; calculates an index value based on the search sequence; reads a hit-rate score from the hit-rate score field of an entry of the prior read command data structure identified by the index value; determines whether the hit-rate score is less than a threshold; and in response to determining that the hit-rate score is less than the threshold, updates the prior read command data structure with the search sequence. Other embodiments are provided.

Storage system and method for hit-rate-score-based selective prediction of future random read commands

A system and method for managing data writes in a non-volatile memory including SLC and MLC blocks of non-volatile memory and a MLC block health rating data structure tracking relative MLC block health. A controller in the system may be configured to select MLC blocks for receiving host data and then route the host data over a direct MLC write path for healthy blocks, or over a two-step indirect write path that includes a SLC write and a SLC-MLC fold for unhealthy MLC blocks. The method may include assigning a health designation based on BER determined for each MLC block and assigning a direct write number to healthy MLC blocks based on the determined BER that limits the number of program/erase cycles for direct writes for a particular MLC block until a re-assessment of block health is needed.

System and method for dynamic folding or direct write based on block health in a non-volatile memory system

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Santa Clara, CA, United States of America

Guruswamy Ganesh