I am highly skeptical of the real differences between the hardware, nothing I've seen posted here and elsewhere does anything to change my mind. This could easily all be smoke and mirrors done with drivers and by the way: They've done it before.
Well, if some or all of the cards have ECC RAM then in the professional space that does seem like something worth paying for as it should make the cards more reliable when running for a long time. But that alone is a question mark already, but I can't imagine ECC GDDR5 RAM comes cheap so it'd be a reasonable cost if that's what some or all of the cards have.
The real question mark for me is how much Apple will really be charging for these; all the historic arguments for the pro cards have boiled down to drivers, support and stability.
Drivers will most likely be coming from Apple as usual, so while they may make particular efforts to optimise for professional uses and claim that as a suitable cost the same as AMD do, we don't really know anything about that. People have claimed seeing drivers named for the consumer equivalents appearing in Mavericks, but that may not necessarily mean anything as Apple engineers could have started writing the drivers for consumer cards slotted into current Mac Pros for example. We just don't know yet, so it's very much an either or case on drivers I think.
Support is presumably going to be typical Applecare, though I really would like to see Apple start bundling Applecare with its pro products at the very least, but we know we're not really paying any extra for this. Plus Apple's support for GPUs hasn't been very good so far; they'll get a few important updates sure, but it's unlikely the drivers will see much continuous development.
Stability is one I realise I've never actually seen proven; I've seen articles describing that pro cards are designed to run at a steady speed for a long time without any performance issues, while the consumer cards aren't quite as reliable, though for games etc. the demands are variable anyway so it doesn't matter. If it's true then it could well be an area where gaming cards and pro cards are genuinely different with gaming cards better at changing their workload and pro cards better at maintaining theirs, but I dunno. ECC is the only concrete feature I can really think of on stability and iirc that's pretty recent for GPUs, but that's very much a prolonged use-case. It would be interesting if someone could set up some very long running (several days at least) benchmarking tests that could be run on a pro card and its consumer equivalent, as that may very well show some real differences for once.
Manufacturing is the one where I think Apple will most likely (and genuinely) be able to justify any cost, as they seem to be assembling the cards themselves so that means they have to make back all the development expenses, costs of machinery and manufacturing etc. And what they're producing is a sort-of passively cooled professional level GPU, so it's not a small accomplishment, and not a cheap one either. Of course the margins are going to be high, but then it's Apple
But yeah you're right, I thought there were more concrete articles showing differences between pro and consumer cards, but there does seem to be very little real evidence to any of it. You'd think someone would have come out with more specifics on actual hardware used.
For example; components in a pro card may undergo more thorough testing with a lower threshold for rejection, whereas consumer cards will ship with chips that are "good enough" (still working obviously, but maybe lose performance under extreme strain). Same question for the memory, the capacitors, etc. etc. These are all things that it'd be reasonable to expect are made/tested to a higher standard in a pro card, but no-one seems to have actually come out and said as much.
