Transcript (PPTX, Unknown)

THE DUMMIES GUIDE TO
COMPUTER MEMORY
JACK BRUTON
RAM AND ROM – WHATS THE DIFFERENCE ?
RAM
ROM
RANDOM ACCESS MEMORY
READ ONLY MEMORY
VOLATILE MEMORY
NON-VOLATILE MEMORY
ALLOWS YOU TO RUN SEVERAL
PROGRAMS AT ONCE, ALTHOUGH CAN
SLOW DOWN OR CRASH IF FULL
STORES THE INSTRUCTIONS THAT THE
COMPUTER NEEDS TO BE ABLE TO BOOT
UP
A RAM CHIP IS PLUGGED IN TO THE
MOTHERBOARD, AND CAN BE CHANGED
A ROM CHIP IS ATTACHED TO THE
MOTHERBOARD
THE DATA IS ERASED AS SOON AS THERE IS THE DATA IS NOT ERASED WHEN THE
NO ELECTRICITY RUNNING THROUGH IT,
COMPUTER IS SWITCHED OFF, IT IS
IT JUST FORGETS
STORED PERMANENTLY
RAM – WHAT DOES IT DO ?
RAM IS USED AS A FAST, TEMPORARY MEMORY THAT STORES :

THE OPERATING SYSTEM

APPLICATIONS

THE GRAPHICAL USER INTERFACE ( GUI )
IT IS USED TO RUN THESE BECAUSE THE COMPUTER IS ABLE TO RUN THEM MUCH
FASTER, RATHER THAN LOADING IT UP FROM THE HARD DRIVE.
HOW MUCH RAM DO YOU NEED ?
RAM IS NEEDED TO RUN PROGRAMS AND IF YOU :

DON’T HAVE ENOUGH – IF ALL OF YOUR RAM IS FULL THEN YOUR COMPUTER IS
LIKELY TO CRASH, BUFFER OR FREEZE.
YOU CAN ADD RAM CHIPS TO YOUR MOTHER BOARD BUT ONLY IF THERE IS A SLOT FOR
IT TO GO IN. SOME COMPUTERS HAVE SPACE FOR 1, 2, 3 OR 4 CHIPS BUT THERE ARE
DIFFERENT SIZES OF CHIP.
SOME TAKE 4 Gb CHIPS, OTHERS TAKE 8 Gb chips, but differnt chips cannot be
interchanged.
WHAT IS VIRTUAL MEMORY ?
VIRTUAL MEMORY IS USED WHEN THE RAM IS FULL. IT ALLOWS YOU TO RUN MORE
OF THE PROGRAMS WITHOUT THE BUFFERING. IF YOU CONSTANTLY USE YOUR
COMPUTER WITH FULL RAM, NORMALLY YOUR COMPUTER WILL CRASH, BUT
SOMETIMES IT USES VIRTUAL MEMORY TO KEEP RUNNING.
VIRTUAL MEMORY IS PART OF THE SECONDARY STORAGE, GENERALLY A MAGNETIC
HARD DRIVE, WHICH ALLOWS THE COMPUTER TO KEEP RUNNING.
BUT THE VIRTUAL MEMORY CAUSES THE SECONDARY STORAGE TO WORK TOO
HARD, AND CAN CAUSE DAMAGE. THIS IS KNOWN AS ‘MEMORY THRASHING’ AND
CAN EVENTUALLY BREAK THE HARD DRIVE.
TO PREVENT THIS, RATHER THAN USING VIRTUAL MEMORY, ADDING MORE OR
BIGGER RAM CHIPS CAN HELP.
CACHE MEMORY – WHAT IS IT ?

THIS IS ANOTHER BIT OF RAM, GENERALLY SRAM (STATIC RAM) THAT JOINS
ONTO THE CPU.

IT ALLOWS THE PROGRAMS TO GET THE INSTRUCTIONS FROM THE FASTER SRAM
INSTEAD OF ACCESSING THE SLOWER DRAM.

THIS IS ALSO KNOWN AS CPU MEMORY AND IS CONNECTED DIRECTLY WITH
THE CPU CHIP OR PUT ON A SEPARATE CHIP AND CONNECTED ONTO A
SEPARATE BUS WITH THE CPU.
FLASH MEMORY – WHAT IS IT ?

THIS IS A WAY TO STORE DATA

IT COULD STORE THE DATA AS 1’S AND 0’S

IT CAN TELL THE DIFFERENCE THROUGH A STRONG BURST OF ELECTRICITY

THIS IS WHERE IT GOT ITS NAME, FROM THE ‘FLASH’ OF ELECTRICITY

IT IS ABLE TO REMEMBER THE STATES AND SO CAN REMEMBER ALL OF THE DATA
DRAM
A memory chip that depends upon an applied voltage to keep the stored data.

DYNAMIC RANDOM ACCESS MEMORY

ONE OF THE MOST COMMONLY FOUND RAM MODULES

IT STORES ITS INFORMATION IN A CELL CONTAINING A CAPACITOR AND
TRANSISTOR

THIS MEANS IT CONSTANTLY NEEDS TO BE REFRESHED WITH BURSTS OF
ELECTRICITY

IF THIS DOES NOT HAPPEN IT WILL JUST LOSE ITS MEMORY
SRAM
a type of memory chip which is faster and requires less power than dynamic
memory.
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STATIC RANDOM ACCESS MEMORY

THIS IS A COMPUTER MEMORY THAT REQUIRES A CONSTANT POWER FLOW TO
HOLD INFORMATION

THIS IS MUCH QUICKER THAN DRAM

IT IS, HOWEVER, MUCH MORE EXPENSIVE AND HOLDS MUCH SMALLER AMOUNTS
OF DATA IN EACH VOLUME