PC SUBSYSTEMS AND COMPONENTS

SYSTEM BOARD [1] 
* chipset[2] 
* BIOS 

PROCESSOR SUBSYSTEM [1] 
* CPU - floating point unit  
	L1 cache 
 	L2 cache 
* Memory 

GRAPHICS SUBSYSTEM
* Controller 
	firmware 
	RAM 
	driver 
* Monitor[3]

DISK SUBSYSTEM (SCSI)
* Controller
 	firmware 
	cache -
	driver 
* Hard/Removable Drives 
	firmware 
	buffer 
* CD-ROM Drive 
	firmware
	 buffer

FLOPPY SUBSYSTEM
* Controller 
	firmware 
* Drives 
	firmware
	 buffer

COMMUNICATIONS SUBSYSTEM (56K) [4]
* Port 
* Modem 
	firmware
	driver
Notes
[1] Component of all subsystems 
[2] Determines speeds of the various buses  
[3] Factor in image quality, not performance 
[4] Performance also affected by external connect factors: line, routing, network, servers.