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 physical location of memory that the CPU is addressing in RAM travels via the Address Bus
- 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
Memory clock (MHz) = 100 - 266
Bus Clock (MHz) = 200 - 533
Data Rate (MT/s) = 400 - 1066
Transfer Rate (Gbps) = 3 - 8
- up to 16BG per DIMM
DDR4
Memory clock (MHz) = 200 - 400
Bus Clock (MHz) = 800 - 1600
Data Rate (MT/s) = 1600 - 2133
Transfer Rate (Gbps) = 12 - 25
- up to 64GB per DIMM
DDR5
Memory clock (MHz) = 200 - 400
Bus Clock (MHz) = 2400 - 3200
Data Rate (MT/s) = 4800 - 6400
Transfer Rate (Gbps) - 64 -128
- up to 128GB per DIMM
DIMM
Dual Inline Memory Module
SO-DIMM
Small Outline Dual Inline Memory Module
- 32 or 64 bit pathways
- used for laptops
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
2.52 used in laptops
Access Time
Speed at which memory can be addressed and utilized
Internal Transfer Rate
Speed at which read/write operations are preformed
External Transfer Rate
Speed at which memory can be transferred to the CPU across the bus
Early-Life Failure Rate
Rate at which a device could fail
