![](/images/new-backgrounds/1109871/10987129x1.webp)
4.0Performance characteristics
This section provides detailed information concerning
4.1Internal drive characteristics
| ST3450856SS | ST3300656SS | ST3146356SS |
|
| ST3450056SS | ST3300056SS | ST3146756SS |
|
Drive capacity | 450 | 300 | 146 | Gbytes (formatted, rounded off value)* |
Read/write data heads | 8 | 6 | 3 |
|
Tracks per inch | 150,000 | 150,000 | 150,000 | TPI |
Peak bits per inch | 1,100 | 1,100 | 1,100 | KBPI |
Areal Density | 165 | 165 | 165 | Gbits/inch2 |
Internal data rate | 1.95 | 1.95 | 1.95 | Gbits/sec (max) |
disk rotation speed | 15k | 15k | 15k | RPM |
Avg rotational latency | 2.0 | 2.0 | 2.0 | msec |
*One Gbyte equals one billion bytes when referring to hard drive capacity. Accessible capacity may vary depending on operating environment and formatting.
4.2Seek time
See Section 9.4.1, "SAS physical interface" on page 62 and the SAS Interface Manual (part number 100293071) for additional timing details.
4.2.1Access time
Not Including controller overhead1, 2 (msec)
|
| Read | Write |
Average | Typical | 3.4 | 3.9 |
Single track | Typical | 0.20 | 0.44 |
Full stroke | Typical | 6.43 | 7.12 |
1.Typical access times are measured under nominal conditions of temperature, voltage, and horizontal orientation as measured on a representative sample of drives.
2.Access to data = access time + latency time.
Cheetah 15K.6 SAS Product Manual, Rev. B | 11 |