Seagate Enterprise Capacity 3.5 HDD v7 SAS Product Manual, Rev. C
16
4.0
Performance characteristics
This section provides detailed information concerning performance-related characteristics and features of Enterprise Capacity 3.5 HDD v7 drives.
4.1
Internal drive characteristics
Drive capacity
12TB models
(formatted, rounded off value)
Read/write data heads
16
Bytes/track
2,265,088
Bytes (average, rounded off values)
Bytes/surface
714,500
MB (unformatted, rounded off values)
Tracks/surface (total)
395,250
Tracks (user accessible)
Tracks/in
392,000
TPI (average)
Peak bits/in
2,283,000
BPI
Areal density
923
Gb/in
2
Internal data rate
2685
Mb/s (max)
Disk rotation speed
7200
RPM
Avg rotational latency
4.16
ms
4.1.1
Format command execution time
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 LBA's = 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)
5xxE-byte sectors (minutes)
12TB models
Maximum (with verify)
1983
Maximum (without verify)
995
