How to identify what Hard Disk Drive you have in your computer or iPod.
Understanding the Acronyms
|Apple 1986 ~ 1993 Machines : Type used SCSI 50p (A.K.A Scuzzy 50 Pin)
|Apple 1994 ~ 2007-08 : Machines Type used IDE 68p (A.K.A IDE/ ATA, ATAPI, Ultra ATA)
|Apple 2008 ~ 2009 Machines Type used SATA (A.K.A Serial ATA)
Small Computer System Interface, or SCSI (pronounced scuzzy. SCSI is most commonly used for hard disks and tape drives, but it can connect a wide range of other devices, including scanners and CD drives. Since its standardization in 1986, SCSI has been commonly used in the Apple Macintosh systems.
IDE/ ATA / PATA:
Advanced Technology Attachment ( ATA/ATAPI ), an interface for computer storage devices
History and terminology
IDE and ATA-1
The second ATA interface
EIDE and ATA-2
Apple started usingParallel ATA (also known as IDE) for its low-end machines with the Macintosh Quadra 630 in 1994, and added it to its high-end desktops starting with the Power Macintosh G3 in 1997. Apple dropped on-board SCSI completely (in favor of IDE and FireWire) with the Blue & White G3 in 1999.
SATA / Serial ATA:
The Serial ATA (SATA, pronounced /set/set/ or/set/) computer bus is a storage-interface for connecting host bus adapters (most commonly integrated into laptop computers and desktop motherboards) to mass storage devices (such as hard disk drives and optical drives).
Conceptually, SATA (Serial Advanced Technology Attachment) is a 'wire replacement' for the older AT Attachment standard (ATA). Serial ATA host-adapters and devices communicate via a high-speed serial cable.
SATA offers several compelling advantages over the older parallel ATA/"EIDE" interface: reduced cable-bulk and cost (7 pins vs 40 pins), faster and more efficient data transfer, and the ability to remove or add devices while operating (hot swapping).
As of 2009, SATA has all but replaced the legacy ATA (retroactively renamed Parallel ATA or PATA) in all shipping consumer Apple computers.
Cache / Buffer Memory:
Cache memory is a cache used by the central processing unit of a drive to reduce the average time to access memory. The cache is a smaller, faster memory which stores copies of the data from the most frequently used main memory locations.
As long as most memory accesses are cached memory locations, the average latency of memory accesses will be closer to the cache latency than to the latency of main memory.
When the processor needs to read from or write to a location in main memory, it first checks whether a copy of that data is in the cache. If so, the processor immediately reads from or writes to the cache, which is much faster than reading from or writing to main memory.
RPM (Revolutions per Minute):
The number of full rotations completed in one minute around a fixed axis. It is most commonly used as a measure of rotational speed or angular velocity of some mechanical component. RPM used in Hard drives are 5400 RPM, 7200 RPM, 10000, 15,000 RPM
The fastest “enterprise” HDDs spin at 10,000 or 15,000 rpm, and can achieve sequential media transfer speeds above 1.6 Gbit/s. and a sustained transfer rate up to 125 MBytes/second.
Hard Disk Drive / HDD:
A hard disk drive (often shortened as "hard disk" or "hard drive"), is a non-volatile storage device which stores digitally encoded data on rapidly rotating platters with magnetic surfaces.
Sizes of Hard Drives:
|| 54 mm
|| iPod / MP3 Players
|| SCSI/ IDE / SATA
|| 69.9 mm
|| SCSI / IDE or SATA
|| 102 mm
|| Personal Computers
Disk formatting is the process of preparing a hard disk or other storage medium for use, including setting up an empty file system.
Hard Drives can be formated for both Mac & PC machines