As educated individuals, we should not label others as “crazy” as it is an insult to those suffering from “acute transient mental disorders.” However, today’s article is not about people but about the brain of computers. What? The CPU, which silently contributes to our daily work, can also have its “crazy” moments? Not quite. The flaws we are discussing today are mostly not about the CPU’s “intelligence” but rather its “health.” Even such flaws have become headlines in IT news because the central processing unit remains the brain of our work and life. Once again, I invite you to walk through history and reflect on those profound and regrettable CPU defects.
1: The CPU Can’t Even Do Math? Time: 1994, Main Character: Pentium, Flaw: FDIV Bug
In June 1994, Intel had just launched its groundbreaking product—the Pentium processor. Just days before the chip’s release, Intel’s technicians discovered a certain deviation in the division operation of the Pentium chip during testing, which could result in an error once in 90 billion division operations.
The Intel testers, with a sense of luck, believed that very few people would be affected by this calculation error and decided to proceed with the launch of the Pentium chip as planned. However, rigorous academic personnel still found this division bug within that minuscule probability.
If you are bored, you can use your computer calculator to calculate the result of 962306957033 ÷ 11010046 = 87402.6282027341 to ten decimal places.
Did you notice any differences in the above two images?
And the defective Intel Pentium CPU result: 962306957033 ÷ 11010046 = 87339.5805831329.
Foreign websites provided detailed explanations of this bug.
This is the FDIV flaw. The FPU unit of the Pentium CPU had serious defects affecting the FDIV (floating-point division) instruction. Although the occurrence of this defect was extremely low, the scientists who discovered this bug still made it public. Users who were using this batch of Pentium CPUs were thrown into a panic, and Intel’s phone lines were overwhelmed. Because the most basic arithmetic correctness could not be guaranteed 100%, this bottom line being breached led to a loss of trust in the three letters CPU.
Feeling the pressure, Intel had no choice but to announce that their CPU had defects and implemented recall and other remedial measures. To this day, while Intel’s subsequent CPUs still have various defects, they have not encountered the most basic arithmetic errors again, as this is a fundamental bottom line.
2: The