Wirth’s Law is a well-known saying in computer programming that states, “Software is getting slower more rapidly than hardware becomes faster.” That creates a problem as the software slows down despite the hardware’s improved processing power.
The law is attributed to Niklaus Emil Wirth, who expressed it in a 1995 paper titled “A Plea for Lean Software.” Wirth was a Swiss computer scientist considered as one of the pioneers of computer science. He helped design major programming languages, including Pascal and Oberon. According to Wirth, the major reason behind the slowdown of software is their complexity.
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Wirth’s Law contradicts Moore’s Law, which states that the number of transistors on a chip doubles even as prices are halved. In essence, Moore’s Law means that the speed and performance of computers increase every two years.
But Wirth’s Law says otherwise. It espouses that despite advancements in hardware capacity and speed, the software cannot become as fast. The rate at which software becomes slower far outruns that at which hardware gets faster. But why is this so?
The Need for Lean Software
In his paper “A Plea for Lean Software,” Wirth espouses that software are getting slower because of “fat.” Fat software refer to complex applications that eventually require more processing power. Therefore, they still slow performance down despite having powerful hardware. Wirth cited these reasons for the drive toward software complexity:
- Adopting all features that users want: Customers tend to confuse features (nice to have) with functionality (necessary functions). Still, software vendors try to make their customers happy by inserting all the features they demand. That results in fat software for which customers pay for all features but actually use only a handful.
- Misconstruing complexity as sophistication: According to Wirth, “people seem to misinterpret complexity as sophistication.” The more complicated a product is, the more polished or knowledgeable the user would appear. Hence, software vendors create complex software and send this marketing message.
- Not having enough time to develop software: Lastly, the reason behind the prevalence of fat software is that engineers simply are not given enough time to plan and design. Wirth said that “time pressure gradually corrupts an engineer’s standard of quality and perfection.”
Other Reasons behind Wirth’s Law
Complex software are not the only ones to blame for the truth behind Wirth’s Law. Incompatibility between software and hardware also plays a role. For example, installing Windows 10 on a computer designed for Windows 7 would result in poor performance.
The presence of computer malware would also impact a computer’s performance. So no matter how optimized your software and hardware are, if they are laden with malware, then you would still experience slow performance.
A slow Internet connection would also affect any web-based application’s speed, regardless of computer power.
Other experts have come up with similar adages, such as:
- Gate’s Law: The speed of software halves every 18 months.
- May’s Law: Software efficiency halves every 18 months, compensating Moore’s Law.
An inside joke among computer scientists is this version of Wirth’s Law: “What Intel giveth, Microsoft taketh away.” The saying means that Intel’s powerful hardware becomes overshadowed by the complexity of Microsoft software.
Several computer experts believe that Wirth’s Law is true. While complex software are the major perpetrators, other reasons come into play. Any software’s speed is affected by its design, Internet connection speed, hardware compatibility, and other factors.
Whatever the reason, Wirth’s Law highlights the need for lean software development, which has now become an accepted trend.