HP ProDesk 490 G2 Quickspecs page 29

QuickSpecs
Technical Specifications – Hard Disk and Solid State Storage
technology enables the intelligent manageability or management software to generate a fault alert. While the current versions of
SMART hard drives do a good job monitoring the data on the hard drive media, the ever increasing emphasis on reliability and
quality has promoted HP to implement SMART IV technology which constantly checks that the data flow from host interface to
media and media to host interface is not compromised. This is accomplished by inserting a 2 byte parity code into every 512 byte
block in the data path of the hard drive's Cache RAM. This unique parity checking performed by HP's SMART IV technology hard
drives, allows for more complete error detection coverage encompassing the entire data path between the host and the hard drive.
Smart IV is also known as IOEDC: I/O Error Detection Code.
Native Command Queuing
NCQ or Native Command Queuing is a SATA protocol extension that allows the hard drive to have several write or read commands
outstanding at the same time. In contrast, normal non-queued operation requires each command to be completed before the next
command is issued by the host system. Queuing allows the drive to complete the commands in the order that allows for best
overall throughput. It also involves an advanced method of transferring data to or from the host, called First Party Direct Memory
Access (FPDMA), which allows the hard drive and the host controller to manage the data transfers for multiple outstanding
commands, without involving the host processor. NCQ can contribute to better performance but the results are dependent on
many factors, including the access patterns of the various applications and operating system functions that are initiating drive
accesses. Enabling NCQ features in the hard drive requires AHCI support from the host system BIOS, controller, and driver. AHCI
support is typically implemented in RAID configurations.
Note: GB = 1 billion bytes. Actual available capacity is less.
2TB 7.2K rpm SATA 6.0Gb/s 3.5" Hard Disk Drive
Unformatted Capacity
Rotational Speed
Interface
Cache, Multisegmented (MB)
Seek Time
(average)
Height
Width
Depth
Weight
Operating Temperature
1TB 7.2K rpm SATA 6.0Gb/s 3.5" Hard Disk Drive
Capacity
2 TB
7,200 rpm
SATA 6 Gb/s
64 MB
Read <8.5 ms
Write <9.5 ms
1.028 in/26.11 mm
4.0 in/101.6 mm
5.787 in/146.99 mm
1.38 lb/626 g
41° to 131° F (5° to 55° C)
1,000,204,886,016 bytes
Worldwide — Version 1.8— May 22, 2014
HP ProDesk 490 G2 Microtower Business PC
Page 29