I took it to mean "at 800MHz, it performs on the same level of some chips that clock in at 1GHz", kind of like how AMD used to label their chips by "equivalent

I took it to mean "at 800MHz, it performs on the same level of some chips that clock in at 1GHz", kind of like how AMD used to label their chips by "equivalent Intel GHz" rather than their literal speed. Like you said, clock speed is not really the issue.