One of my own quotes from another thread:
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"This is true sometimes but not other times man
.. Even "in theory".. When a new request comes in, you have to account for the probability of it requesting info from the HDD that is already processing stuff. Then that goes into the probability of the 1st HDD actually "doing" something at any given time.. And before u know it, when trying to setup the equations, your head will explode and you will die.
So the moral of this: trust the benchmark. lol
But, yeah. The "maximum" throughput "ever" possible is 2x the throughput of a single drive. But the theoretical throughout should be lower as it accounts for all time in probabilistic terms.
."
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Essentially, the 2x the speed is only realized "sometimes" as the coordination of the 2 HDDs is not guaranteed given the requests.. I think benchmarks are the most reliable. And they indicate the Raptor is faster than a Raid 0 setup of 7200 rpm.