3.2 Given a scenario, Install the appropriate RAM Flashcards
What happens when a process is executed?
Image is loaded from disk into memory
Instructions are fetched from system memory & into the CPU’s cache & registers as required. This process is handled by the memory controller
How is system memory implemented as?
RAM
Meaning of RAM?
Random Access Memory
What is RAM faster than?
Hard drives
What does it mean that RAM is volatile?
Only stores data when powered on
What does the amount of system RAM determine?
PC’s multitasking & handling of large files
What does pagefile or swap space refer to?
Portion of a hard drive reserved for virtual memory
What does virtual RAM refer to?
Using storage to supplement physical RAM
With virtual RAM, what does the OS do?
Assigns memory to processes in 4KB pages
Why does the OS use a page-based systen in Virtual RAM?
To move inactive pages to swap space to free up RAM
Swap space is a portion of a storage drive used as virtual memory when the physical RAM is full. It temporarily holds inactive memory pages, freeing up RAM for active processes.
Why does paging slow down the computer?
This is related to virtual RAM
Disk transfer rates are slower than RAM transfer rates
Another purpose of virtual RAM besides supplementing physical RAM with storage?
To protect the operation & integrity of a PC
How can virtual RAM protect a PC?
Allowing the OS to manage shared virtual memory for multiple processes
Virtual memory abstraction enhances system security and stability by centrally managing memory allocation, preventing process interference, and enforcing security measures, surpassing the reliability of direct access to physical RAM for each process.
What type of memory is mainly used in modern computer systems?
DDR SDRAM (aka RAM)
Meaning of DDR SDRAM?
Double Data Rate Synchronouse Dynamic Random Access Memory
3 types of memory used in computer systems?
- DRAM
- SDRAM
- DDR SDRAM
How does Dyanmic RAM (DRAM) store data?
As electrical charges in bit cells, each compromising a capacitor
A transistor reads whether the capacitor hold a charge, representing 1, or not, representing 0
Why is Synchronous DRAM (SDRAM) so-called that way?
Its speed is synchronized to the motherboard system clock
How does DDR SDRAM add on to SDRAM?
Makes 2 data transfers per clock cycle
This effectively double the data transfer rate compares to traditional SDRAM
How are DDR memory modules labeled?
Using the max theoretical bandwidth
i.e. PC1600, PC2100, etc.
In this memory example - DDR-200 PC-1600 - What does DDR-200 mean?
Data rate of 200 MT/s
MT/s = Megatransfers per second
The DDR-200 designation signifies a 100MHz internal memory clock speed. With DDR, the effective data rate doubles the clock speed, resulting in 200 MT/s
In this memory example - DDR-200 PC-1600 - What does PC-1600 mean?
Peak transfer rate of 1600 MBps (1.6 GBps)
PC-1600” signifies the memory’s peak transfer rate, calculated by multiplying the data rate (200 MT/s) by the bytes transferred per operation. With DDR memory doubling the transfer rate by operating on both edges of the clock signal, and each transfer carrying 8 bytes (64 bits), the peak rate reaches 1600 MBps (1.6 GBps).
How do subsequent generations of DDR technology increase bandwidth?
“subsequent generations of DDR technology” refers to DDR2, DDR3, DDR4, & DDR5
By multiplying the bus speed
This produces scalable speed improvements without making the memory modules too unreliable or hot. Design improvements also increase the max possible capacity of each memory
Data rate of DDR3 RAM?
Up to 2133 MT/s
Transfer rate of DDR3 RAM?
Up to 17.06 GB/s
Max size of DDR3 RAM?
8 GB
This means that a single RAM module can have a max capacity of 8GB
What is a memory module?
A PCB grouping RAM devices as a single unit
Memory modules are produced in different capacities. Each DDR generation sets an upport limit on the max possible capacity
What memory module do desktops use?
DIMM
The notches on the edge connector identify the DDR generation and ensure proper insertion. DDR DIMMs often have heat sinks due to high clock speeds
Meaning of DIMM?
Dual-Inline Memory Module
What are memory modules vulnerable to?
ESD
Always take anti-ESD precautions when handling & storing these devices
What speeds should memory modules match for optimal performance?
Motherboard’s bus speed
What occurs if memory modules with different speeds are installed on the MOBO?
MOBO = Motherboard
System runs at the speed of the slowest component
What memory modules do laptops use?
SODIMM
Meaning of SODIMM?
Small Outline DIMM
What does dual-channel memory mean?
There’s 2 64-bit pathways through the bus to the CPU
This means that 128 bits of data can be sent per transfer rather than 64 bits.
For dual-channel configuration, consult system documentation to find correct slots. Motherboards usually have 4 DIMM slots in color-coded pairs, each pair representing a channel
What may you need to do to use Multi-channel memory?
Enable it via PC’s firmware settings
Why do ECC RAM modules have an additional processor chip?
To handle data error correction tasks
