Memory and Storage (Chapter 3) Flashcards
System memory
The memory that the system uses to execute calculations
Data Bus
Computational information that will be read/written on RAM by the CPU travels via this bus
- The width of the pathway determines the amount of data transferable per clock cycle
- 64 bits wide
Address Bus
The bus in which memory address is transferred
- Width of address bus determines the amount of memory locations the CPU can keep track of
- x32 bit system with 32-bit address bus can access 4GB of memory
- x64 bit system with 48-bit address bus can access 256TB of memory
RAM Types
DRAM - Dynamic Random Access Memory
- needs constant refreshing
SDRAM - Synchronous Dynamic RAM
- Synchronized to system clock
DDR SDRAM - Double Data Rate SDRAM
- Synchronized to double the system clock rate
DDR3
Data transfer (MT/s) = 800 - 2133
Transfer Rate (Gbps) = 3 - 8
- up to 16BG per DIMM
- 240 pins
- 1.5 - 1.35v
DDR4
Data Rate (MT/s) = 1600 - 2133
Transfer Rate (Gbps) = 12 - 25
- up to 64GB per DIMM
- 288 pin
- 1.2v
DDR5
Data transfer (MT/s) = 4800 - 6400
Transfer Rate (Gbps) - 64 -128
- up to 128GB per DIMM
- 288 pins
- 1.1V
DIMM
Dual Inline Memory Module
SO-DIMM
Small Outline Dual Inline Memory Module
- 32 or 64 bit pathways
- used for laptops
DDR3 & 3L
- 204pin
-3L = low voltage SO-DIMM
DDR4
- 260pine
DDR5
-262pin
Parity & ECC RAM
Parity RAM
- An error checking method where each byte of memory is accompanied by a ninth bit that is used to check if the data is corrupted
ECC Error Correcting Code
- detects and corrects errors on the fly
Hard Disk Drives (HDD)
A devices that provides non-volatile mass storage space via magnetic disks.
- Data is written on concentric rings called tracks
- the tracks are then further divided into sectors. Up to 4096-Byte sectors
- up to 8 TB storage
3.5” used in desktops
2.5” used in laptops
Access Time
Speed at which memory can be addressed and utilized
Internal Transfer Rate
The read/write operation speed at which the drive is capable of
External Transfer Rate
Speed at which data can be transferred to the CPU across the bus
Early-Life Failure Rate
Rate at which a device could fail
Mean time Between Failures (MTBF)
rating on a devices that predicts the time between failures
Life Expectancy
The length of time a device is expected to be operational for
S.M.A.R.T.
A standardised Technology across all storage drives designed to alert users of potential disk failure