2 Ways to Increase Computer System Performance
Overview
This post discusses two methods of increasing computer performance, specifically, through the FSB and microarchitecture. There are many methods to increase performance, the decision to focus on these was arbitrary and based on curiosity. Regardless, this post will provide an overview of computer performance and how the microarchitecture and Front Side Bus can be utilized to increase performance.
Introduction
Improving computer system performance is paramount to pushing the boundaries of innovation. At the system level, factors that affect performance are CPU, RAM, and the overall architecture of the system (“Factors That Affect CPU Performance”). Each of these factors have their own factors that affect performance. For example, CPU performance factors include the instruction set, clock speed, bandwidth, front side bus speed, and on-board cache; again, each of these factors have their own factors that affect performance. That is the beauty of abstraction. There are many routes that can be taken to improve performance at the system level; each route comes with its own trade-offs. When seeking to improve performance, we must identify where the bottlenecks are occurring. Two factors that contribute to system performance are the microarchitecture and front side bus speed.
Microarchitecture
Before we can understand what microarchitecture is, we must understand the instruction set architecture. In short, the instruction set architecture is an abstraction of your computer system. It provides the basic tools which allow for CPU’s of varying implementations. The microarchitecture is located one abstraction layer below the ISA, and one abstraction above the computers registers and counters (Lundman). The microarchitecture is a high-level structure of circuitry organization for a system responsible for: the number of functional units, the memory hierarchy, the input and output interfaces, the order of the functional units in the pipeline, the number of clock cycles units have for computation, and branch prediction and data forwarding logic (Chinnery and Keutzer). According to Chinnery and Keutzer, microarchitectural changes are the most significant way of increasing computer performance. For example, pipelined circuits allow for higher clock frequency. The clock frequency is raised due to the combinational delay of each pipeline decreasing. Pipelining in addition allows us to implement parallelism, which increases both the calculations per second and the calculations completed (Chinnery and Keutzer).
Front Side Bus
An additional way to increase performance is to increase the maximum rate at which data can be transferred to the rest of the system. Transferring data at faster rates may be accomplished through enhancing Front Side Bus (FSB) speed. The FSB is the interface between the processor and the system memory. The FSB may limit the rate at which data can get to the CPU, which inevitably limits the rate at which the CPU can process that data. In essence, the CPU derives its clock speed from the FSB. This can be described by the formula CPU Clock = FSB * Clock Multiplier (Shimpi). Increasing FSB is a method known as overclocking the CPU. An additional upside is that this method is easily configurable, as most systems provide user functionality to adjust FSB speed. A downside to this however, is that overclocking increases the FSB speed for all components on the system motherboard, and if taken too far, can lead to performance issues (Shimpi). So when overclocking, one must be cognitive of the capabilities of their system components.
Works Cited
Shimpi, Anand Lal. “AMD Athlon Overclocking Guide.” RSS, AnandTech, 25 Jan. 2000, https://www.anandtech.com/show/457/3.
Chinnery, David & Keutzer, Kurt. “Closing the Gap Between ASIC & Custom: Tools and Techniques for High-Performance ASIC Design”, Boston, MA, Kluwer Academic Publishers, 2002
Lundman, Susan. “A Quick Introduction to Instruction Set Architecture and Extensibility” embedded, www.embedded.com/a-quick-introduction-to-instruction-set-architecture-and-extensibility/. Accessed 30 January 2022.
“Factors Affecting CPU Performance” kitchentablecomputers, https://www.kitchentablecomputers.com/processor2.php#:~:text=The%20CPU%27s%20FSB%20speed%20determines,chipset%2C%20and%20the%20RAM%20speed.
