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Improving the performance score of Multi-thread Sequential Write

IP.com Disclosure Number: IPCOM000014555D
Original Publication Date: 2000-May-01
Included in the Prior Art Database: 2003-Jun-19
Document File: 1 page(s) / 28K

Publishing Venue

IBM

Abstract

Disclosed is a method of improving the performance score of multi-thread sequential write operation of HDD (Hard Disk Drive) with Write Cache enabled. The performance score of multi-thread sequential write is almost same as that of random write, and it is much less than the value of the thread number times the performance score of single-thread sequential write operation, because seek operation must be done to switch from a thread to another. In order to improve the performance score of multi-thread sequential write, it is very effective to reduce the number of seek operations by combining write commands of each thread to execute them as a write command. The cache search engine of HDD can be used to combine the write commands of a thread with the multi-segmented sector buffer architecture. When HDD starts execution of a write command, it tries to find any sequential access by using the cache search engine. If Write Cache is enabled, there may be some segments in which data of cached write commands have been transferred. The cache search engine can detect any sequential write to one of the segments. If a sequential write access to one of the segment is detected, the HDD has only to start the data transfer in the segment just after the previously transferred data in order to combine them. The combined data can be written to the media as one write command. 1

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Improving the performance score of Multi-thread Sequential Write

    Disclosed is a method of improving the performance score of multi-thread sequential write
operation of HDD (Hard Disk Drive) with Write Cache enabled. The performance score of multi-thread
sequential write is almost same as that of random write, and it is much less than the value of the
thread number times the performance score of single-thread sequential write operation, because seek
operation must be done to switch from a thread to another. In order to improve the performance score
of multi-thread sequential write, it is very effective to reduce the number of seek operations by
combining write commands of each thread to execute them as a write command.

The cache search engine of HDD can be used to combine the write commands of a thread with the
multi-segmented sector buffer architecture. When HDD starts execution of a write command, it tries
to find any sequential access by using the cache search engine. If Write Cache is enabled, there may
be some segments in which data of cached write commands have been transferred. The cache search
engine can detect any sequential write to one of the segments. If a sequential write access to one
of the segment is detected, the HDD has only to start the data transfer in the segment just after the
previously transferred data in order to combine them. The combined data can be written to the media
as one write command.

1