Mobile i5s always had hyperthreading from the beginning.

Edit: nope, actually, I'm wrong - Core i5-430M was a straight dual core, no hyperthreading part.

Originally, my memory says "i7 meant 4+ core & hyper threading", "i5 meant 4 cores w/o HT", "i3 meant 2 cores (with or without HT)".

But I'm sure even at the beginning there were SKUs that broke the coding due to customer demand.

I think the lesson here is that Intel's marketing for these chips has been a mess from day one.

Some of it is inevitable, they have too many aspects to contain in a reasonable product name, but letting the names become divorced from any sort of reality helps nobody.

I'm writing this on a dual core i3 with hyper threading.