Question

A CPU executes instructions at the rate of \(1000 \mathrm{MIPS}\). Data can be copied 64 bits at a time, with each word copied costing 10 instructions. If an coming packet has to be copied four times, can this system handle a 1-Gbps line? For simplicity, assume that all instructions, even those instructions that read or write memory, run at the full 1000-MIPS rate.

Short answer

Yes, the system can handle a 1-Gbps line as it processes 1.6 Gbps.

Step-by-step solution

Analyze the CPU's Instruction Rate

The CPU executes at a rate of 1000 MIPS, which means it performs 1000 million instructions per second (\(1000 \times 10^6 \) instructions/second).

Determine Number of Instructions for Copying

Each 64-bit word copied costs 10 instructions. The packet needs to be copied four times, thus requiring \(4 \times 10 = 40\) instructions per word copied.

Calculate Bits Processed per Second by the CPU

The CPU can execute \(1000 \times 10^6 \) instructions per second. Since each copy of a 64-bit word takes 10 instructions, the CPU can handle \( \frac{1000 \times 10^6}{40} \) 64-bit words per second.

Convert 64-bit Words to Bits

The CPU processes \( \frac{1000 \times 10^6}{40} = 25 \times 10^6 \) 64-bit words per second. Each word is 64 bits, so the total is \(25 \times 10^6 \times 64\) bits per second.

Compare to Required Bitrate

Simplifying the product: \(25 \times 10^6 \times 64 = 1.6 \times 10^9\) bits per second (or 1.6 Gbps). The system can handle a 1-Gbps line, as it exceeds the required throughput.

Key concepts

MIPS

The term MIPS stands for Million Instructions Per Second, which is a measure of a CPU's performance. It indicates the number of millions of instructions a CPU can handle every second. In the context of computer performance, MIPS is used to compare how different CPUs perform in executing instructions.

Understanding MIPS helps evaluate whether a CPU can handle certain tasks or applications. For example, a CPU rated at 1000 MIPS can process 1,000 million instructions per second. In measuring CPU performance, MIPS provides a quantifiable metric that gives insights into how efficiently a CPU can execute various tasks.

• MIPS allows quick benchmarking of CPU performance.
• It helps assess the capability to handle complex software applications.

Data Transfer Rate

Data transfer rate is a term used to describe the amount of data transferred from one location to another within a specific time frame. It is usually measured in bits per second (bps). The data transfer rate is an essential factor in determining the performance of computing systems, networks, and devices.

In computer systems, data transfer rate could relate to the speed at which data is moved between components, such as from memory to the CPU. For example, if a CPU executes a task that involves copying data, understanding the data transfer rate helps in evaluating whether the CPU can match the speed required by external connections, like network lines.

• It's crucial for assessing network and system performance.
• A higher data transfer rate can enable faster communication and processing.

Instructions per Second

Instructions per second (IPS) is a measurement of how many instructions a computer's central processing unit (CPU) executes in one second. This measure provides a direct indication of the CPU's computational speed and ability to handle various tasks efficiently.

In practical terms, understanding instructions per second helps in planning processing loads and capabilities. For instance, when evaluating a system for data-intensive tasks, knowing the instructions per second capability ensures that the system can meet its performance requirements without bottlenecking.

• Instructions per second directly impact system responsiveness and task completion times.
• A higher IPS value typically means more efficient processing capabilities.

Bitrate Calculation

Bitrate calculation involves determining the number of bits processed or transferred per unit of time, typically measured in bits per second (bps). Bitrate is a critical metric in understanding the performance and capability of a data transmission system.

In scenarios involving data packets and network connections, calculating the bitrate helps gauge if the data flow can meet or exceed the required data transmission rates. For instance, in the exercise, the system processes bits at a rate exceeding the 1 Gbps requirement, handling 1.6 Gbps, which allows for seamless data processing and transfer.

• It is essential in evaluating network bandwidth and device throughput.
• Accurate bitrate calculation ensures efficient data handling and maximizes system performance.