RAM (Random Access Memory) Flashcards
What is RAM?
Random Access Memory.
The storage for short-term memory.
Most RAM is ____, which means that it can be erased/wiped if it isn’t saved or the power is turned off suddenly.
volatile
What is the relationship between CPU cache and RAM?
Cache is built into most CPU’s nowadays to provide an even shorter-term memory for the CPU to do its work. RAM can’t quite keep up with the CPU, but it does still hold short-term memory. Hard drives hold longer-term memory data.
What are the different types of RAM?
- DRAM (Dynamic Random Access Memory)
- SDRAM (Synchronous Dynamic RAM)
- DDRSDRAM (Double Data Rate Synch. Dynamic RAM)
- DIMM (Dual Inline Memory Module)
Dynamic Random Access Memory (DRAM)
When information is sent, DRAM stores each bit in a microscopic capacitator, either 1’s or 0’s. DRAM can be put on memory sticks.
DIMM sticks (Dual Inline Memory Module)
The most modern memory sticks available. They have different sizes of pins on them. Another name for RAM, but they’re just different designs of pins on the sticks.
What does “synchronous” mean in SDRAM?
Synchronous means that it is synchronized to the system’s clock speed (system crystal), allowing quicker processing of data.
What’s the difference between DDR1 and DDR4?
DDR1 was first developed, then there was DDR2, DDR3, and DDR4 is the fastest type of short-term memory currently available.
What does it say about a system when it has more RAM available than other systems?
More RAM means that the programs run faster and more programs can run at the same time.
What is the only type of RAM stick that has 2 notches?
SDRAM (synchronized RAM)
What is the purpose of DDR SDRAM? (double data rate synch. dyn. RAM)
For any one click of the system clock, this memory gives double the data at one time. It’s faster at giving data to process.
What is a PC speed rating?
We can use this to measure RAM speeds along with DDR ratings. When you measure this way, you take the DDR rate and x by 8 to get the PC rating.
DDR speed x 8 = PC speed rating
DDR2 (double data rate 2 - SDRAM)
- uses a 240 pin design
- twice as fast as DDR
- 4x as fast as core RAM clock speed
DDR3 (double data rate SDRAM)
- uses a 240 pin design
- increased the speed 2x as fast as DDR2
- less power consumption
- DDR and DDR2 are legacy technologies and no longer used in modern devices.
DDR4
- uses a 288 pin DIMM stick, 260 pin DIMM
- fastest RAM that is described on A+
- even less power consumption than DDR3
- the most common RAM stick
- uses bandwidth (mt/sec)
What do you do to the DDR speed to get the PC rating?
You multiply a DDR speed by 8 to get the PC rating.
You can measure RAM speeds by what two things?
- PC ratings
- DDR speed
When you have a certain motherboard and you want to get RAM sticks for it, what’s important to know?
If what you’re buying is compatible with the motherboard.
Different motherboards support different technology.
What are dual-channel memory sticks?
You have to use two sticks of RAM to go in specific places by following the motherboard book. These sticks have the same speed and the same capacity.
Dual channels provide access to two RAM modules at the same time.
Triple-channel memory
Using 3 sticks of RAM to go in specific places (with the same speed and capacity) to help the computer run faster
When you’re using multiple channeled memory, you should make sure that the sticks are _____ in the same channel
identical / the same
Read the motherboard book. Use two sticks of RAM with the same speed and capacity.
Most RAM sticks have 8 chips, except for ______.
Parity/ECC RAM
Parity/ECC RAM - Error Correction Code RAM
- A special type of RAM that contains an extra chip to check for RAM single-bit errors or failures.
- For each byte (eight bits) of memory, a parity bit is set that will allow the logic to detect and correct an error in a single bit of each byte.
- These sticks can function with a failed memory chip.
- Extremely expensive.
- Only for motherboards that can support it (and have to have it).
SO-DIMMs (small outline Dual Inline Memory Module)
- smaller alternative to a regular DIMM
- used in smaller systems (laptops, tablets, printers, and network hardware)
- small form factor motherboards
- often have the same speed ratings as regular DIMM but at a smaller capacity
- commonly found in laptops where space is at a premium and come in 100-, 144-, 200-, 204-, and 260-pin configurations.
- SODIMM defines the physical form factor of the module.
SPD Chip (Serial Presence Detector)
- almost all RAM has this.
- stores information about the RAM itself.
- queries information about capacity, DDR speed, different RAM slots, manufacturer, model number
- you need special software downloaded to access it.
When you’re installing RAM sticks, what should you consult first?
The motherboard manual.
The manual will tell you what RAM it takes, as well as the capacity and speed of it.
The most common problems with installing RAM sticks are?
- Not clicked in correctly
- Channel problem
- Wrong type of RAM (wrong speed or capacity)
When putting new RAM into a system, you need to do what on boot up?
Watching that the system “sees” the installed RAM.
If there’s a problem with the RAM in a question, what is the LAST thing to think about or assume?
That the RAM sticks are bad or non-functional. Usually it’s an install problem, channel problem, or the wrong type of RAM.
What’s the purpose of using dual channeled memory?
Dual channels provide simultaneous access to two RAM modules when reading or writing. Triple channel memory uses 3 sticks of RAM, while four channel uses 4. These help the computer grab memory as fast as possible.
virtual RAM
space on a hard drive that can be allocated when additional memory is requested from an application. This space on the hard drive is also known as a swap file or a paging file
single channel memory
transfers data in chunks the same size as the system’s bus’ bandwidth
dual channel memory
occurs when the memory controller coordinaties two memory banks to work in conjunction with one another as a synchronized set when communicating with the CPU, doubling the size of the data transfer.
triple channel memory
coordinates three memory modules for communication with CPU.
quad channeled memory
coordinates 4 memory modules for communication with CPU
