CPU & friends
What does the Program Counter (PC) hold?
The memory address of the next instruction.
Is RAM volatile or non-volatile?
Volatile.
What are the 3 stages of the instruction cycle?
Fetch, Decode, Execute.
Give one example of external storage.
USB, external HDD/SSD, SD card.
Why is compression important?
Saves space, speeds transfer.
What does the MAR store, and how does it interact with memory?
Holds address of data/instruction; sends it via the address bus to RAM.
What is stored in ROM?
BIOS/firmware for startup.
What does the MDR do in the fetch stage?
Holds instruction/data fetched from RAM.
What does NAS stand for? Is it internal or external?
Network Attached Storage.
Lossy vs Lossless compression?
Lossless = no data lost; Lossy = data lost, smaller files.
What is the purpose of the Instruction Register (IR)?
Temporarily stores the current instruction before decoding.
What is a cache hit vs a cache miss?
Hit = found in cache; miss = must fetch from slower memory.
Why is the instruction cycle vital for all computer operations?
Every program runs through it billions of times/sec.
Compare SSD vs HDD speed.
SSDs are faster (2,500–7,000 MB/s vs 100–200 MB/s).
What is SaaS? Give an example.
Software as a Service, apps over the internet.
What is the function of the Accumulator?
Stores intermediate results of calculations.
Compare registers, cache, and RAM in speed & size & distance from CPU
Registers fastest/smallest/inside CPU, cache very fast (L1 is on the CPU, L2&3 are close), RAM larger/slower, farthest from CPU
How does PaaS differ from IaaS?
PaaS Provider manages OS/environment, and IaaS gives raw infrastructure only.
Why is GPU architecture better for machine learning than CPU?
Thousands of cores optimized for parallel matrix operations vs a few CPU cores for sequential tasks.
Why does virtual memory slow down performance?
Uses HDD/SSD, which is slower than RAM.
Why is elasticity important in cloud computing?
Scale resources up/down instantly, cost-efficient.