CGS2100 Exam 2 Evaluating your system There is NO ideal machine that will work for EVERYONE Computer technology advances very quickly aka becomes outdated fast Moore s Law Gordon Moore of Intel States that central processing unit CPU power doubles every 2 years o Capacity of DRAM chips increases 60 annually Hard Drive increases 50 annually Kinds of Users Casual Users o Uses computer for internet access mostly o Uses some software applications Microsoft Office o Uses video and software but does NOT create them Power Users Mobile Users o Need fast powerful processing o Need fast abundant storage o Creates videos and software programs o Needs lightweight device with long battery life o Happy to sacrifice functionality for less weight What kind of device do you need Main distinction need for mobility VS need for processing power o On the go users ultra book tablet notebook Desktops are usually a good option o More computing power ability to upgrade system components reliable due to stationary nature o Lasts 2 6 years o System evaluation looking at computers subsystems seeing what they do and how they perform on tasks Determines whether your computer is still meeting needs o CPU usage gives information about how hard you CPU works and on what tasks Task Manager Windows Activity Monitor OS X Will vary depending on open programs but if it is working HARD most of the time upgrade machine o CPU Benchmarks measurements used to compare performance between processors To check which CPU is best for you CPU Subsystem CPU is located on the mother board is responsible for processing instructions performing calculations and managing flow of information On a PC you can check type of CPU through System Properties o Most popular brands of processors Intel AMD Composed of 2 units Control Unit Arithmetic Logic Unit o CU coordinates activities of all other computer components o ALU performs all arithmetic calculations logic decisions and comparisons Machine Cycle process for CPU performing a program instruction o Gets required data from RAM o Decodes instructions for computer o Executes instructions o Stores results in RAM before getting next instruction This process serves as the basic unit of work performed by a processor Factors that affect a CPU s performance o Clock Speed o Number of Cores How many machine cycles the CPU performs each second Measured in gigahertz GHz billions of cycles per second Between 2 1 4 GHz Faster clock speed more instruction can be processed in a given time Overclock runs at high clock speed than intended Leads to increase in CPI performance but decrease in CPU lifetime Processor with multiple cores means there are multiple processors running on the same chip Dual Core Processors can process 2 instructions simultaneously Hyper threaded each core can execute multiple programs at the same time by interleaving their instructions Form of really fast memory that resides close to the processor Allows processor to keep data instructions close by Doesn t have to go back to RAM to find them o Cache Memory Clock Speed Multiple Cores Power Users Important would even overclock Want as many as possible Casual Users Not that important Fewer is fine Mobile Users Not that important Lower power draw number of cores Cache Memory Would pay for more Hell no save your Same Memory Subsystem RAM random access memory temporary storage of data for CPU for programs currently running o Volatile storage because data is cleared when computer is turned off o Also called physical memory o Measured in gigabytes GB usually 4GB 32GB ROM read only memory permanent storage that hold instructions needed to boot computer o Non volatile storage i e hard drive because it s used to hold data even when the computer is turned off Faster for the CPU to access RAM than ROM hard drive RAM means you have more space to hold currently active programs o More space you have more programs can run without CPU having to access hard drive o Most common RAM Double Data Rate 3 DDR3 memory modules Speeds 1066 1333 1600 MHz DDR5 used in high performance graphics cards Memory Modules Card small circuit boards that hold series of RAM chips and fit into slots on mother board o RAM appears in system on these Dual Inline Memory Modules DIMM can hold several memory chips Checking total RAM o Windows System properties window o OS X Apple menu About this mac You need enough RAM to run your operating system o Buy as much as you can Storage Subsystem Mechanical Hard Drive has the largest capacity of any storage device at more than 4 TB also most economical A hard drive is composed of platters o Platters coated round thin plates of metal which are stacked on a spindle Pattern of magnetized spots is aligned in one direction to represent 0 and the other direction to represent 1 Access Time time to find and retrieve date from a hard drive o Approx 12 milliseconds Solid State Drive SSD uses electronic memory instead of mechanical motors moving parts o Have an access time of about 0 1 millisecond over 100x faster than o Many computers offer a 20GB SSD system drive which is used to mechanical hard drives hold OS so boot up is faster o SSD good option for ultra books because lower resiliency o Very expensive o Most computers only have 128 GB or 256 GB of SSD available as options Hard drive capacity is measured in gigabytes GB or terabytes TB o 1 terabyte 1000 gigabytes 500 GB is usually good but if you use cloud storage stream heavily you can even just use 50 GB Someone who stores media photographer will need multiple terabytes or external hard drive Optical Drives disc drives that use a laser to store and read data saved on optical media CD DVD Blu ray o Non volatile storage o Primary means in delivery of music music programs but has been slightly replaced by streaming downloading o Many lightweight systems don t include optical drive anymore Can purchase external optical drives Video Subsystem How video is displayed depends on two components video card monitor o Video Card Adapter expansion card that s installed inside system unit to translate binary data into the images you view on your monitor Modern video cars allow you to connect to video equipment with DVI ports digital LCD monitors HDMI ports HD TV Blu ray gaming consoles Display Port adapter digital monitors or projectors Major video card manufacturers NVIDIA AMD have standards for combining video cards NVIDIA standard is called SLI AMD standard is called Crossfire X Video cards that can
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