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4.0
Performance characteristics
This section provides detailed information concerning performance-related characteristics and features of Exos X16 drives.
4.1
Internal drive characteristics
Drive capacity
Read/write data heads
Bytes/track
Bytes/surface
Tracks/surface (total)
Tracks/in
Peak bits/in
Areal density
Internal data rate
Disk rotation speed
Avg rotational latency
4.1.1
Format command execution time
5xxE-byte sectors (minutes)
Typical (with verify)
Typical (without verify)
Execution time measured from receipt of the last byte of the Command Descriptor Block (CDB) to the request for a Status Byte Transfer to the
Initiator (excluding connect/disconnect).
When changing sector sizes, the format times shown above may need to be increased by 30 minutes.
4.1.2
Fast Format
Drive sector size transition
• Single code to support sector sizes from 512E
• T10 fast format conversion between 512E configurations in the field.
• Possible only if sector sizes are exact multiples of 8 & vice versa
• The selected sector size will take effect only after fast format or full format
• Drive default is 512E from the factory.
• 512E features set after Fast Format
T10 Fast Format
• Implements the fast format based on T10 Spec.
• To request Fast Format, the FFMT bits (Byte 4, Bits 1:0) should be set to 01b.
• A setting of 10b or 11b will return a check condition with 05/24 sense code (pointing to FFMT MSB in CDB).
Mode Select - Parameter list header
• Set Write buffer: // Set Block Descriptor Length = 0x08, Number of LBAs = 0xFFFFFFFF
• 00 00 00 00 00 00 00 08 FF FF FF FF 00 00 02 00 // Set block size to 0512 (0x0200)
• Then Send Mode Select Command
• cdb: 55 01 00 00 00 00 00 00 10 00 // (SP bit = 1, Parameter list = 0x10)
Format Unit - Parameter list header
• Set Write buffer: // Set IMMED = 1
• 00 02 00 00
• Then Send Format Unit Command
• cdb: 04 14 00 00 01 00 // (FMTDAT = 1, DEFECT LIST FORMAT = 010b, FFMT = 01b)
Seagate Exos X16 SAS Product Manual, Rev. D
16TB
14TB
18
16
1,842,878
1,842,878
889,000
889,000
487,200
487,200
423,000
423,000
2,362,000
2,362,000
1000
1000
2772
2772
7200
7200
4.16
4.16
16TB models
2740
1372
Performance characteristics
(formatted, rounded off value)
Bytes (average, rounded off values)
MB (unformatted, rounded off values)
Tracks (user accessible)
TPI (average)
BPI
2
Gb/in
Mb/s (max)
RPM
ms
18
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