68020 vs. 68040

Attribute	68020	68040
Release Year	1984	1990
Transistors	190,000	1,200,000
Performance	14.9 MIPS	34.1 MIPS
Address Bus	32-bit	32-bit
Data Bus	32-bit	32-bit
Cache	None	8 KB

The 68020 and 68040 processors are both members of the Motorola 68000 series of microprocessors, which were widely used in personal computers and workstations during the late 1980s and early 1990s. While both processors share some similarities, they also have distinct differences in terms of performance, features, and compatibility. In this article, we will compare the attributes of the 68020 and 68040 processors to help you understand their strengths and weaknesses.

Performance

One of the key differences between the 68020 and 68040 processors is their performance capabilities. The 68020 processor is a 32-bit processor with a clock speed ranging from 12 to 33 MHz, while the 68040 processor is a more advanced 32-bit processor with clock speeds ranging from 25 to 40 MHz. This means that the 68040 processor is generally faster and more powerful than the 68020 processor, making it better suited for demanding tasks such as multimedia applications and graphic design.

Additionally, the 68040 processor features a built-in floating-point unit (FPU) which allows for faster mathematical calculations compared to the 68020 processor, which requires an external FPU for similar performance. This gives the 68040 processor a significant advantage in tasks that involve complex mathematical operations, such as 3D rendering and scientific simulations.

Features

Another important aspect to consider when comparing the 68020 and 68040 processors is their features. The 68040 processor includes a number of advanced features that are not present in the 68020 processor, such as an integrated memory management unit (MMU) and a larger on-chip cache. The MMU in the 68040 processor provides better memory management capabilities, allowing for improved multitasking performance and virtual memory support.

Furthermore, the 68040 processor also includes a branch prediction unit and a data cache, which help to improve overall performance by reducing the number of memory accesses and increasing the efficiency of instruction execution. These features make the 68040 processor more efficient and capable of handling complex tasks with greater ease compared to the 68020 processor.

Compatibility

When it comes to compatibility, the 68020 and 68040 processors have some differences that may impact their usability in certain systems. The 68020 processor is fully compatible with software and hardware designed for earlier members of the 68000 series, such as the 68000 and 68010 processors. This makes it a good choice for systems that require backward compatibility with older software and peripherals.

On the other hand, the 68040 processor is not fully compatible with software and hardware designed for earlier 68000 series processors, due to its more advanced architecture and features. While most software can be recompiled to run on the 68040 processor, some older applications may not work properly without modifications. This can be a drawback for systems that rely on legacy software or peripherals.

Conclusion

In conclusion, the 68020 and 68040 processors have distinct differences in terms of performance, features, and compatibility. The 68040 processor offers superior performance capabilities, advanced features, and improved efficiency compared to the 68020 processor. However, the 68020 processor may be a better choice for systems that require backward compatibility with older software and hardware.