68040 vs. 80486

Attribute	68040	80486
Manufacturer	Motorola	Intel
Release Year	1990	1989
Instruction Set	68k	x86
Max Clock Speed	40 MHz	33 MHz
Cache Size	8 KB	8 KB
Transistor Count	1.2 million	1.2 million

Introduction

When it comes to computer processors, the 68040 and 80486 are two of the most well-known chips from the late 1980s and early 1990s. Both processors were designed to provide high performance for their time, but they had some key differences in terms of architecture, features, and capabilities. In this article, we will compare the attributes of the 68040 and 80486 processors to help you understand their strengths and weaknesses.

Architecture

The 68040 processor, developed by Motorola, was a 32-bit chip that featured a superscalar architecture with multiple execution units. This allowed the 68040 to execute multiple instructions in parallel, improving overall performance. In contrast, the 80486 processor, developed by Intel, was also a 32-bit chip but featured a more traditional CISC (Complex Instruction Set Computing) architecture. While the 80486 did have some pipelining capabilities, it was not as advanced as the 68040 in terms of parallel execution.

Performance

When it comes to performance, the 68040 and 80486 processors were both considered high-end chips for their time. The 68040 was known for its fast clock speeds, reaching up to 40 MHz in some models. It also had a large on-chip cache, which helped improve performance by reducing memory access times. The 80486, on the other hand, was also known for its speed, with clock speeds reaching up to 100 MHz in later models. However, the 80486 did not have as large of a cache as the 68040, which could impact performance in certain tasks.

Features

One of the key differences between the 68040 and 80486 processors was the presence of certain features. The 68040, for example, had built-in floating-point unit (FPU) for handling mathematical calculations, which was essential for tasks like graphics rendering and scientific computing. The 80486, on the other hand, did not have a built-in FPU in all models, requiring users to purchase a separate math coprocessor for these tasks. Additionally, the 68040 had support for virtual memory and memory protection, which made it more suitable for multitasking operating systems.

Compatibility

When it comes to compatibility, both the 68040 and 80486 processors were designed to be backward compatible with previous generations of software. However, the 80486 was known for its strict adherence to the x86 instruction set, which made it compatible with a wide range of software applications. The 68040, on the other hand, had some compatibility issues with older software that was not optimized for its architecture. This could be a drawback for users who needed to run legacy applications on the 68040.

Power Consumption

In terms of power consumption, the 68040 and 80486 processors had different characteristics. The 68040 was known for its relatively high power consumption, which could lead to heat generation and require more robust cooling solutions. The 80486, on the other hand, was more power-efficient, thanks to its advanced manufacturing process and lower clock speeds. This made the 80486 a more attractive option for users who were concerned about energy efficiency and heat dissipation in their systems.

Conclusion

In conclusion, the 68040 and 80486 processors were both powerful chips that offered high performance for their time. The 68040 excelled in areas like parallel execution, on-chip cache size, and support for advanced features like virtual memory. The 80486, on the other hand, was known for its compatibility with a wide range of software applications, energy efficiency, and lower power consumption. Ultimately, the choice between the 68040 and 80486 would depend on the specific needs of the user, whether they prioritize raw performance or compatibility with existing software.