IT Computer Architecture 2 — Questions and Answers
Question 1: What is virtual memory?
- Physical RAM installed on the motherboard
- A technique using disk space to extend the apparent RAM capacity (Correct answer)
- A fast cache between the CPU and main memory
- Memory used exclusively by the OS kernel
Correct answer: A technique using disk space to extend the apparent RAM capacity
Virtual memory uses a portion of disk storage to simulate additional RAM, allowing systems to run programs larger than available physical memory.
Question 2: What does DMA (Direct Memory Access) allow a peripheral device to do?
- Access CPU registers without OS permission
- Transfer data directly between the device and memory without CPU intervention (Correct answer)
- Encrypt data before storing it in memory
- Share memory addresses among multiple processes
Correct answer: Transfer data directly between the device and memory without CPU intervention
DMA lets peripheral devices transfer data to and from main memory autonomously, freeing the CPU for other tasks during bulk data transfers.
Question 3: What is the purpose of the Program Counter (PC) register?
- Count the number of programs running simultaneously
- Track CPU performance metrics over time
- Store the memory address of the next instruction to be fetched (Correct answer)
- Hold the result of the most recent arithmetic operation
Correct answer: Store the memory address of the next instruction to be fetched
The Program Counter holds the address of the next instruction to fetch, advancing sequentially to guide the CPU through a program.
Question 4: Flynn's Taxonomy classifies parallel computer architectures based on which two dimensions?
- Memory type and processor speed
- Instruction streams and data streams (Correct answer)
- Clock speed and cache size
- Number of cores and bus width
Correct answer: Instruction streams and data streams
Flynn's Taxonomy uses the number of simultaneous instruction streams and data streams to classify architectures as SISD, SIMD, MISD, or MIMD.
Question 5: In little-endian byte ordering, how is a multi-byte integer stored in memory?
- Most significant byte at the lowest memory address
- Least significant byte at the lowest memory address (Correct answer)
- Bytes are stored in a randomized order
- All bytes share the same memory address
Correct answer: Least significant byte at the lowest memory address
Little-endian stores the least significant byte at the lowest memory address, with byte significance increasing as addresses increase.
Question 6: What is the primary advantage of a multicore processor?
- It operates at a higher clock frequency than single-core CPUs
- It enables true parallel execution of multiple threads simultaneously (Correct answer)
- It consumes less power than any single-core processor
- It requires less cache memory per core
Correct answer: It enables true parallel execution of multiple threads simultaneously
Multiple independent CPU cores allow genuinely simultaneous execution of separate threads or processes, improving throughput for parallel workloads.
Question 7: What is the von Neumann bottleneck?
- The limited number of registers available to programs
- A throughput limit caused by a single shared bus for both instructions and data (Correct answer)
- The maximum transistor count that fits on a chip
- Heat dissipation constraints in modern processors
Correct answer: A throughput limit caused by a single shared bus for both instructions and data
The von Neumann bottleneck arises because the CPU and memory share one bus, forcing instructions and data to compete for the same limited transfer pathway.
IT Computer Architecture 2
What is virtual memory?