Performance Characteristics; Internal Drive Characteristics; Format Command Execution Time; Fast Format - Seagate EXOS ENTERPRISE 2X18 SAS 512E Standard Product Manual

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4.0

Performance characteristics

This section provides detailed information concerning performance-related characteristics and features of Exos 2X18 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

512E sector sizes
(minutes)
Maximum (with verify)
Maximum (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
Seagate Exos 2X18 SAS Product Manual, Rev. A
18TB 16TB
18 16
1,754,393 1,754,393
1,008,949 1,008,949
543,200 543,200
463 463
2470 2470
1144 1144
2898 2898
7200 7200
4.16 4.16
18TB models
1471
758
(formatted, rounded off value)
Bytes (average, rounded off values)
MB (unformatted, rounded off values)
Tracks (user accessible)
kTPI (average)
kBPI
2
Gb/in
Mb/s (max)
RPM
ms
16TB models
1308
674
Performance characteristics
11