View Single Post
MacInWin

 
MacInWin's Avatar
 
Member Since: Jul 07, 2008
Location: Winchester, VA
Posts: 3,111
MacInWin has much to be proud ofMacInWin has much to be proud ofMacInWin has much to be proud ofMacInWin has much to be proud ofMacInWin has much to be proud ofMacInWin has much to be proud ofMacInWin has much to be proud ofMacInWin has much to be proud ofMacInWin has much to be proud of
Mac Specs: 2011 MBP, 2008 iMac, iPhone 5S, iPad mini, 13" MBP and MacMini

MacInWin is online now
Quote:
Originally Posted by Exodist View Post
The reason a HDD slows down is due to the placement of the data on the platers of the HDD. When data first gets placed on the drive, it is placed to the center of the drive. Thus when the arm that holds the read/write heads moves, it has a shorter distance to move to gather the data. When it has to move to the outside of the platters the segments are generally spaced further apart due to rotation speed and it takes the drive longer to find and move the data.

A SSD on the other hand, it just RAM chips and no mechanical slow downs are present..


Hope this explains..
Actually, modern drives use Zone Bit Recording (ZBR) which adds more blocks to tracks further from the spindle. Instead of having the same number of blocks on each track, the longer tracks at the outer edge have more blocks, hence more data. The tracks are grouped in zones of adjacent tracks and the number of block in the zone increases from the center out by zone. The object is to have the bits/second remain relatively constant as the heads move from the faster outer tracks to the slower inner tracks.

As a result of this technology, the fastest transfers from disks now occur on the outer tracks, so the drives use the space there first, then move inward to where there are fewer zones and slower data transfers. The tracks are all the same distance apart, so the fact that outer tracks have more data in them mean that the heads can sit on one track longer, reducing the total time to transfer because there are fewer head movements on the outer tracks.
QUOTE Thanks