> Naturally, if you can look at a program which is now twice as fast and be unimpressed you are looking at the wrong metric.
Or, a computer scientist would say, the right one. The actual speed doesn't matter as much as the complexity.
In reality, it does, in the end; but it's also important to consider the type of optimization you're doing, and not just stop at being impressed with twice as fast.
For example, a primitively optimized function that's twice as fast for input size 100 would still be twice as fast for input size 100,000, but a function optimized to be an order less complex could be twice as fast for size 100, and a thousand or so times as fast for size 100,000.
The latter optimization would be significantly better, objectively, and thus, it would make a lot of sense to look at the first program and be unimpressed with a mere linear doubling in speed.
Or, a computer scientist would say, the right one. The actual speed doesn't matter as much as the complexity.
In reality, it does, in the end; but it's also important to consider the type of optimization you're doing, and not just stop at being impressed with twice as fast.
For example, a primitively optimized function that's twice as fast for input size 100 would still be twice as fast for input size 100,000, but a function optimized to be an order less complex could be twice as fast for size 100, and a thousand or so times as fast for size 100,000.
The latter optimization would be significantly better, objectively, and thus, it would make a lot of sense to look at the first program and be unimpressed with a mere linear doubling in speed.