fig:- Block diagram of Mother board
- North Bridge [GMCH]
- [Graphic Memory Controller Hub]
It controls graphic and memory sections of MotherBoard.Graphic section includes VGA port,AGP or pcl express slot & Memory stands for DIMM Slot [RAM]
- All data from these Port travels to CPU through GMCH so,any fault in GMCH block the data transmission from CPU to RAM & hence no data outs at dispaly
- South Bridge [ICH]
-[Input Output Controller Hub]
It control all sections except graphic & Memory but all section are not directly controlled by this chip.Few other ICs are used between input - output section & ICH
-The section ICH controls directly are USB,PCI,SATA,PATA,BIOS,RTC crystal,Audio IC,LAN IC,SIO IC.
- SIO
-[Serial Input Output IC]
It works under south Bridge & controls PS/2 port (KB,Mouse).Seriial Port,Parallel Port,Floppy Port,fan,speed & power switch.
- RAM
-[Random Acess Memory]
It hold data during working of computer.The processed data by CPU is placed into RAM whhich is further sent to display through North Bridge.
Types of RAM used in computer
-SD-RAM
i. It has two cut and pin type IC.
ii. It works on 3.3V
iii. It has 164 pins
iv. It is used in Pentium III computers/speed 100 to 200 MHz
-DDR I
Fig :- DDR I
i. It has one cut and pin type IC.ii.It works on 2.5V.
iii. It has 184 pins.
iv. Used in earlier Pentium IV computers /speed 200 to 400MHZ
-DDR II
i. It has 240 pins & speed 400-800 MHz
ii. One cut and works on 1.8V
-DDR III
i. It has also single cut but broad height is smaller than other RAM
ii. It works on 1.5V
iii. Speed 800-1600 MHz.