ITHELPDESK

RAID – Redundant Array of Independent Disks           RAID concept was developed by University of California at Berkeley in 1987.       RAID arrays are used to improve the reliability & performance of Hard disks.       RAB (RAID Advisory Board) was formed in 1992 to standardize RAID concepts.     Standard RAID levels advised by RAB are       Hybrid (Nested) RAID levels                RAID 10 (1+0)                     RAID 01 (0+1)           The most common RAID types used today are explained below Ø RAID 0 – Disk Striping §   Spreading the data between multiple drives (at least 2 drives) is called data striping. §   Increases hard drive access speed (High read/write performance) §   No redundancy §   File data is divided into blocks and spread in a fixed order among all the disks in the array. §   If any one of the physical disks fails, the whole logical volume will fail, resulting in the computer crash and requiring to recover the data from

To do system board upgrades & provide better recommendations to clients, technicians need to know their form factors. 1. AT Form Factor - Advanced Technology i. Invented by IBM in the early 1980's ii. Around 12" wide * 13" deep iii. Only designed to handle keyboard and monitor, lack of external ports required.  2.     ATX Form Factor - Advanced Technology Extended i. Designed by INTEL in 1995 ii. Around 12" * 9.6" in size iii. Built-in double high external I/O connector panel, hence external ports can be located directly on the board iv. Single main keyed internal power supply connector, hence the power connector is easy to plug & can't be installed incorrectly. v. Relocated CPU & memory next to the power supply which improved airflow cooling. Also reduced the interference with any bus expansion cards. vi. Relocated internal I/O connectors for the hard drives & the floppy drives near the drive bays to shorten the c

Enclosure or Case Encases all the components of a computer. Square or rectangular in shape. Made of steel, Aluminium or plastic.       ⦁ Power supply Provides power to the components of the computer. Rated in Watts (A unit of power). Mostly 250 to the 400-watt range. Converts 110 Volt or 220 Volt  AC current to the DC voltages required to operate. The required voltages may be +3.3 VDC, + 5 VDC, -5VDC  (ground), +12 VDC, -12 VDC (ground) and +5 VDC  standby.       Note:   +3.3 VDC & +5 VDC standby voltages are used only by ATX motherboards, not          AT motherboards.     ⦁ Mo therboard The backbone of the computer, also known as the system board or Planar board. Olive green or brown circuit board that lines the bottom of the computer CPU (Central processing unit), expansion slots, underlying circuitry, video components, RAM (Random Access Memory) slots etc are placed on the system board or Motherboard.   Read more about Motherboard