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| introduction:indefinite_scalability [2015/04/18 22:45] – [Introduction: Hardware determinism] ackley | introduction:indefinite_scalability [2015/05/08 07:08] (current) – ackley |
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| In the traditional approach to digital computing, the physical hardware is required to be //deterministic//: The machine is to operate in clearly-defined discrete steps, and the state of the machine (the values of all its 'bits' collectively) after a step is absolutely and completely determined by the state of the machine when the step began. In the agreement between hardware and software, the hardware is not allowed to produce any surprises or unanticipated conditions: nothing misread or misstated, no oopsies or booboos or broken alarm clocks, no excuses of any kind. If hardware can't perform its duties perfectly, for whatever reason, its final obligation is to kill itself: to crash and "end the world", rather than produce a wrong answer. | In the traditional approach to digital computing, the physical hardware is required to be //deterministic//: The machine is to operate in clearly-defined discrete steps, and the state of the machine (the values of all its 'bits' collectively) after a step is absolutely and completely determined by the state of the machine when the step began. In the agreement between hardware and software, the hardware is not allowed to produce any surprises or unanticipated conditions: nothing misread or misstated, no oopsies or booboos or broken alarm clocks, no excuses of any kind. If hardware can't perform its duties perfectly, for whatever reason, its final obligation is to kill itself: to crash and "end the world", rather than produce a wrong answer. |
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| Deterministic hardware makes the programmer's job much easier are easy to reason about and it has been a remarkable, world-changing success in the marketplace, but it ultimately **scales poorly** and offers **poor security**. But since hardware determinism now underpins so many other design decisions, incremental attempts to move beyond determinism, historically, have struggled to gain traction. | Deterministic hardware makes the programmer's job much easier, and it has been a remarkable, world-changing success in the marketplace, but it ultimately **scales poorly** and offers **poor security**. However, since hardware determinism now underpins so many other computational design decisions, incremental attempts to move beyond determinism, historically, have struggled to gain traction. |
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