C952 Computer Architecture

Explanation:

DDR3 memory features 240 pins and provides several improvements over DDR2, including higher data transfer rates, lower power consumption, and improved latency. DDR3 achieves these improvements by operating at lower voltages and using enhanced signaling techniques. This makes DDR3 both faster and more energy-efficient compared to DDR2, which helps improve overall system performance while reducing power usage in desktop and server environments.

Correct Answer:

It features 240 pins and provides improved latency and power efficiency compared to DDR2.

Why Other Options Are Wrong:

It has 288 pins and offers higher data rates than DDR2 is incorrect because 288 pins are associated with DDR4 memory, not DDR3.

It operates at a single data rate per clock cycle, similar to DDR2 is incorrect because DDR3 is a double data rate memory that transfers data on both the rising and falling edges of the clock cycle, like DDR2, but with higher performance and efficiency.

It is primarily used in mobile devices and was introduced in the early 2000s is incorrect because DDR3 is used broadly in desktops, servers, and some laptops; it was introduced later, around 2007, not in the early 2000s.

Explanation:

A register file is a small, high-speed storage area within the CPU used to hold data temporarily during instruction execution. For it to function properly, the CPU must be able to both retrieve data from the registers (read) and store new or updated data into them (write). This dual capability allows instructions to use the data for processing and then update it as needed for subsequent instructions. Without both read and write access, the register file would not be able to fulfill its role in executing programs efficiently.

Correct Answer:

Read and write access

Why Other Options Are Wrong:

Read only access is incorrect because a register file must allow writing data; if it could only be read, the CPU would not be able to store results or update values.

Write only access is incorrect because the CPU also needs to retrieve the data stored in the registers to perform computations; writing alone is insufficient for normal operations.

No access is incorrect because, without any access, the register file cannot participate in instruction execution at all, making it entirely nonfunctional.

Explanation:

A primary disadvantage of NAS is that its performance depends heavily on network speed and reliability. Since NAS devices communicate over the network, any bottlenecks or latency in the network can reduce data transfer rates, affecting overall system performance. While NAS offers centralized storage, RAID configuration, and user-friendly setup, these benefits are counterbalanced by potential performance limitations due to network dependency, especially in environments with heavy data access or limited bandwidth.

Correct Answer:

Its performance can be affected by network speed and reliability.

Why Other Options Are Wrong:

It provides centralized storage for easy file sharing is incorrect because this is actually an advantage of NAS, not a disadvantage. Centralized storage simplifies file access and collaboration.

It can be configured with RAID for data redundancy is incorrect because RAID support enhances reliability and is a benefit rather than a drawback of NAS systems.

It is user-friendly and easy to set up for all users is incorrect because ease of setup is a positive attribute, not a disadvantage.

Explanation:

Sequential processing is used when a program executes steps one at a time, waiting for user input before proceeding to the next operation. This approach does not overlap tasks; the CPU processes instructions in a strict order and pauses when waiting for external events, such as user input. Sequential processing is simple to implement and suitable for applications that do not require concurrent task execution.

Correct Answer:

Sequential

Why Other Options Are Wrong:

Distributed is incorrect because distributed processing involves multiple computers or nodes working together to execute tasks simultaneously, which does not describe a program waiting for user input.

Parallel is incorrect because parallel processing executes multiple instructions or tasks simultaneously, whereas the program described waits for input and processes tasks one at a time.

Symmetric is incorrect because symmetric processing refers to multiple processors sharing a single memory and operating system in a symmetric multiprocessing system, which is unrelated to sequential execution based on user input.

Explanation:

In 2005, the key shift in computing capability came from the move to multiprocessor architecture, particularly multi-core processors. Before this change, increasing CPU clock speed was the main method of improving performance, but physical and thermal limitations made further clock speed increases impractical. By integrating multiple processor cores on a single chip, systems could perform parallel processing more efficiently, significantly boosting computing performance without increasing clock speed. This shift transformed both consumer and enterprise computing, marking the era of multicore processors as the standard for enhancing computing capability.

Correct Answer:

Multiprocessor architecture

Why Other Options Are Wrong:

Transistor architecture is incorrect because while transistor miniaturization continues to advance, the fundamental design element that drove a major performance leap in 2005 was the move to multiple cores, not just the transistor design.

Frame buffering is incorrect because frame buffering relates to graphics memory handling in video cards and displays. It does not directly enhance overall computing capability in the same transformative way that multiprocessor architecture does.

DRAM technology is incorrect because improvements in DRAM (speed, latency, or density) enhance memory performance but were not the key design change in 2005 responsible for the substantial leap in processing capability.

Explanation:

When CPI (cycles per instruction) remains high despite an increased clock rate, memory latency often dominates performance. Virtual memory, which relies on accessing data from disk when it is not present in RAM, can cause significant delays, resulting in high effective CPI. The CPU may be forced to stall while waiting for pages to be loaded from secondary storage, so even a faster clock cannot compensate for these delays. Therefore, virtual memory access is a primary factor negatively affecting performance under these circumstances.

Correct Answer:

Virtual memory

Why Other Options Are Wrong:

Hard disk drive is incorrect because while the HDD is involved in virtual memory, the performance issue is more broadly caused by virtual memory management, not the disk itself. The disk is a component, but the negative impact arises from the memory hierarchy and page faults.

Single processor is incorrect because having a single processor does not inherently cause CPI to remain high; the performance issue here is due to memory access latency, not processor count.

Cache memory is incorrect because cache memory typically improves performance. High CPI under increased clock rate is indicative of cache misses that escalate to main memory or virtual memory access, not the cache itself being the limiting factor.

Explanation:

Software as a Service (SaaS) refers to software applications delivered over the internet that users can access via web browsers without installing the software locally. Microsoft OneDrive and Office 365 are examples of SaaS because they provide cloud-based applications such as word processing, spreadsheets, and storage that users can access anywhere, with updates and maintenance managed by the service provider.

Correct Answer:

Microsoft OneDrive and Office 365

Why Other Options Are Wrong:

Dropbox is incorrect because while it offers cloud storage, it is primarily a platform for file storage and synchronization, not a full software application suite delivered as a service.

Oracle on Demand is incorrect because it is closer to Platform as a Service (PaaS) or database hosting rather than traditional SaaS applications for end users.

Amazon Simple Storage Service is incorrect because it is an object storage service (IaaS), not software delivered as a service.

Amazon Elastic Cloud 2 is incorrect because it provides virtual computing resources (IaaS), not end-user applications characteristic of SaaS.

Explanation:

RAID 0, also known as striping, splits data across multiple drives to maximize storage capacity and speed. Since it does not use any redundancy, all disk space is available for storage, and read/write operations can occur simultaneously across the drives, providing the fastest performance. This makes RAID 0 ideal for applications like video editing, where large storage space and high-speed access are critical, and data redundancy is less important or handled through backups. The lack of redundancy does mean data is vulnerable if a drive fails, but it meets the requirement for maximum space and speed.

Correct Answer:

RAID 0

Why Other Options Are Wrong:

RAID 6 is incorrect because it provides double parity for redundancy, which reduces available storage space and adds overhead that slows performance. It prioritizes fault tolerance rather than maximum speed or capacity.

RAID 5 is incorrect because it uses single parity, which also reduces available storage and introduces write overhead, slowing performance compared to RAID 0.

RAID 1 is incorrect because it mirrors data across drives, halving effective storage capacity and offering slower write performance due to duplication, making it unsuitable when maximum space and speed are required.

Explanation:

SIMD, which stands for Single Instruction, Multiple Data, describes a parallel computing model where a single instruction is executed simultaneously across multiple data streams. This is commonly used in applications like graphics processing, scientific computing, and multimedia tasks where the same operation must be performed on many data elements at once. SIMD improves performance by exploiting data-level parallelism and reducing the number of instruction fetches needed for repetitive operations.

Correct Answer:

SIMD

Why Other Options Are Wrong:

SISD is incorrect because Single Instruction, Single Data refers to a traditional sequential processing model where one instruction operates on one data element at a time, offering no data-level parallelism.

SPMD is incorrect because Single Program, Multiple Data describes a parallel programming paradigm where multiple processors execute the same program independently on different portions of data, but it does not imply a single instruction operating on multiple data elements simultaneously in hardware.

MIMD is incorrect because Multiple Instruction, Multiple Data refers to a system where multiple processors execute different instructions on different data concurrently, which is more general than SIMD and does not guarantee simultaneous execution of the same instruction on multiple data streams.