When a dual core CPU with Hyper-Threading features is installed on a motherboard, how many instructions can the CPU simultaneously process?

The correct answer is: 4.

When a dual-core CPU with Hyper-Threading is installed on a motherboard, it can process 4 instructions simultaneously. Each core in the dual-core processor can handle 2 threads due to Hyper-Threading, which allows a single core to work on two separate threads at the same time. As a result, a dual-core processor with Hyper-Threading effectively functions as if it has 4 logical cores, allowing it to handle 4 threads simultaneously.

Let’s break down why 4 is the correct answer and explore how Hyper-Threading and dual-core CPUs work.

1. Understanding Dual-Core Processors

A dual-core processor has two physical cores within a single CPU package. Each core can independently process a separate stream of instructions, allowing the CPU to perform two tasks (or threads) simultaneously. Without Hyper-Threading, a dual-core processor would normally only process 2 instructions at once—one per core.

How Dual-Core Processors Work:

Each physical core processes one thread at a time.
With two cores, a dual-core CPU can handle two threads or instructions simultaneously.

2. Hyper-Threading Technology

Hyper-Threading is a technology developed by Intel that allows each physical core of a processor to handle two threads simultaneously. With Hyper-Threading, a single core can switch between two threads quickly, giving the appearance of two logical cores. This increases the efficiency of the CPU by utilizing more of the core’s resources.

How Hyper-Threading Works:

In a CPU without Hyper-Threading, each core can process only one thread at a time.
With Hyper-Threading enabled, each core can handle two threads at once. Although it doesn’t double the core’s performance, it allows better utilization of the CPU’s resources by keeping the core busy.

3. How a Dual-Core CPU with Hyper-Threading Works

When a dual-core CPU with Hyper-Threading is installed, each of the two physical cores can handle two threads simultaneously. This results in the processor being able to handle 4 threads at once (2 threads per core × 2 cores).

Dual-Core with Hyper-Threading Capabilities:

2 physical cores, each capable of processing 2 threads.
4 logical cores in total, from the operating system’s perspective.
The CPU can process 4 instructions simultaneously because it acts like a quad-core CPU from the perspective of the operating system.

This configuration enables the system to perform more tasks in parallel, improving multitasking and the performance of multi-threaded applications.

Why the Other Options Are Incorrect

6 (Incorrect)

A dual-core processor with Hyper-Threading cannot process 6 threads simultaneously. For a CPU to handle 6 threads, it would need 3 physical cores with Hyper-Threading enabled, which is beyond the capacity of a dual-core processor.

8 (Incorrect)

A CPU capable of processing 8 instructions simultaneously would need 4 physical cores with Hyper-Threading, resulting in 8 logical cores (4 cores × 2 threads per core). Since the question specifies a dual-core processor, processing 8 instructions is not possible.

2 (Incorrect)

A dual-core CPU without Hyper-Threading can process 2 instructions simultaneously—one instruction per core. However, with Hyper-Threading enabled, each core can process 2 threads, allowing the CPU to handle 4 instructions in total, making 2 an incorrect answer.

Conclusion

The correct answer is 4 because a dual-core CPU with Hyper-Threading can process 4 instructions simultaneously. Each of the 2 physical cores can handle 2 threads, effectively allowing the CPU to process 4 threads (or instructions) at the same time. This setup provides significant improvements in multitasking and performance for applications that can take advantage of multi-threading.