Set Transfer mode, Write Cache | Hitachi HDS721064CLA332, A7K2000

11.37.2 Set Transfer mode

When Feature register is 03h (=Set Transfer mode), the Sector Count Register specifies the transfer mechanism. The upper 5 bits define the type of transfer and the low order 3 bits encode the mode value.

PIO Default Transfer Mode	00000	000
PIO Default Transfer Mode	00000	001
Disable IORDY
PIO Flow Control Transfer Mode x	00001	nnn	(nnn=000,001,010,011,100)
Multiword DMA mode x	00100	nnn	(nnn=000,001,010)
Ultra DMA mode x	01000	nnn	(nnn=000,001,010,011,100,101,11
			0)

11.37.3 Write Cache

If the number of auto reassigned sector reaches the device‟s reassignment capacity, the write cache function will be automatically disabled. Although the device still accepts the Set Features command with Feature register

=02h without error, but the write cache function will remains disabled. For current write cache function status, please refer to Identify Device Information (word 85 or 129) by Identify Device command.

11.37.4 Serial ATA Feature

When the Feature register is set to 10h or 90h, the value set to the Sector Count register specifies the specific Serial ATA feature to enable or disable.

Sector Count Value	Description
01h	Non-zero buffer offset in DMA Setup FIS
02h	DMA Setup FIS Auto-Activate optimization
03h	Device-initiated interface power state transitions
04h	Guaranteed In-Order Data Delivery
06h	Software Settings Preservation

11.37.5 Advanced Power Management

When the value in the Feature register is 05h (=Enable Advanced Power Management), the Sector Count Register specifies the Advanced Power Management level.

FFh ---		Aborted
C0 – Feh ---		The deepest Power Saving mode is Normal Idle mode
		(the same as Disable Advanced Power Management)
80	– BFh ---	The deepest Power Saving mode is Low power Idle mode
01	– 7Fh ---	The deepest Power Saving mode is Low RPM standby mode
00h ---		Aborted

The idle time to Low power idle mode and Low RPM standby mode vary according to the value in Sector Count register as follows:

When Low power idle mode is the deepest Power Saving mode,

Y1=(x-80h) * 5+120 [sec] (120<= Y1<=435)

Y2=N/A(the device does not go to Low RPM standby mode)

When Low RPM standby mode is the deepest Power Saving mode and the value in Sector Count register is between 40h and 7Fh,

120<=Y1<=435 [sec] (default: 120 [sec])

Hitachi hard disk drive specifications

192 HCS721016CLA382, HCS721050CLA382, HCS721025CLA382, HDP725050GLA360, HUA722050CLA330/1 specifications

Hitachi's lineup of hard disk drives, including models such as HDS721075CLA632, HDS721032CLA362, HDS721032CLA662, HDS721050CLA362, and DSDS7210C09EN-04, offers a variety of features catering to different storage needs. These drives are widely recognized for their reliability, performance, and efficiency, making them suitable for both consumer and enterprise applications.

The HDS721075CLA632 model, with a capacity of 750GB, strikes a balance between performance and storage capabilities. It operates at 7200 RPM, ensuring quick access to data while maintaining low latency. Its 32MB cache enhances data transfer rates and improves overall system responsiveness. This HDD is particularly useful for gaming, multimedia, and office applications, allowing users to store a substantial amount of data with quick retrieval times.

The HDS721032CLA362 and HDS721032CLA662 share many similarities and are both designed for budget-conscious consumers. With a capacity of 320GB and a 7200 RPM, they offer efficient storage solutions for everyday tasks. The 32MB cache buffer enables efficient caching of frequently accessed files, providing a smooth experience for users.

Another notable model is the HDS721050CLA362, which features a capacity of 500GB. Like its counterparts, this drive operates at a speed of 7200 RPM and utilizes a 32MB cache, which ensures optimal performance for data-heavy applications. This model stands out for its energy efficiency, resulting in lower operational costs, making it an appealing choice for businesses and energy-conscious consumers alike.

On the other hand, the DSDS7210C09EN-04 is a part of Hitachi's enterprise-oriented offerings. This drive is engineered for demanding applications, featuring advanced technologies such as error recovery controls and enhanced data protection features. With a focus on reliability and performance, the DSDS7210C09EN-04 serves well in server environments and for high-performance computing.

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Overall, the diverse range of models from Hitachi provides effective solutions for anyone from casual users to enterprises, combining storage capacity with advanced technologies to meet the evolving demands of modern data storage.