lesson 4 memory Flashcards
what is rams main function
the Main memory that the CPU uses to store or receive data
a type of memory that loses its content without power
volatile memory
ROM
Read only memory not volatile
allows the ram to communicate with the cpu
memory controller
a type of memory thaT is very fast and typically used in the Cpu cache
SRAM
Syncs to base clock of mobo (system bus speed)
And needs to be periodically refreshed
synchronous dynamic RAM- 166PIN
a memory chip that is used as main memory. DRAM must be constantly refreshed with pulses of electricity in order to maintain the data stored within the chip
DRAM
Double Data Rate SDRAM is memory that transfers data twice as fast as SDRAM. DDR SDRAM increases performance by transferring data twice per clock cycle.
DDR 184 PIN-2.5 VOLTS
Double Data Rate 2 SDRAM is faster than DDR-SDRAM memory. DDR2 SDRAM improves performance over DDR SDRAM by decreasing noise and crosstalk between the signal wires.
DDR2 = 240 PINS 1.8 VOLTS
Double Data Rate 3 SDRAM expands memory bandwidth by doubling the clock rate of DDR2 SDRAM. DDR3 SDRAM consumes less power and generates less heat than DDR2 SDRAM.
DDR3 - 240 PINS 1.2-1.5 VOLTS
Double Data Rate 4 SDRAM quadruples DDR3 maximum storage capacity, requires 40% less power due to it using a lower voltage and has advanced error correction features.
DDR4 -280 PINS 1.2-1.35 VOLTS
single channel architecture
Original RAM architecture. 64-bit bus (or data channel) between the memory and
the memory controller. One or more sticks of RAM can be installed on the motherboard but they
share the same channel.
dual channel architecture
Doubles the data. Two 64-bit channels are employed together resulting in a 128-bit
bus.
single sided memory module
Single modules with a single bank of chips. Memory module could have chips on
both physical sides or only on one side - It is known as single sided because the computer can address all the
chips at once.
dual sided memory module
Memory modules have their chips divided into two “sides” known as banks. Only
one side can be seen by the computer at once
When memory stores an extra bit (parity bit) used for error detection. So mem module can store 9 bits instead of 8 bits for every byte of data. Required for data integrity.
RAM parity
non parity ram
Nonparity memory does not check for errors in memory.
Error Correction Code in RAM - Can detect and correct errors. Additional information needs to be stored, and
more resources are used. Slowest type of RAM and most expensive. Usually identified with an E. I.e. PC3-10600E
ECC RAM
Happens when a memory controller tries to access data from a memory module. Slight delay
(measured in nanoseconds)
memory latency
always hold ram by the
Edges and employ anti-static measures
unbuffered memory
memory commands in unbuffered memory configurations go directly from the controller to the memory module
buffered memory
Registered memory has a “register” that resides between the RAM and the system’s memory controller which lessens the load that is placed on the memory controller itself
data transfer rate
MT/s (megatransfers/second) x 8 = Data Transfer Rate
ram typically used in laptops
SO-DIMM small outline dimm
Dual inline memory module
DIMM
DDR2 and DDR3 SO-DIMMS have how many pins
200 and 204
DDR4 SO-DIMMS have how many pins
260
ram speed is measured in what
mhz
