True, but cost is just passed right to the consumer.
Apple's stacking their 30+% margin on top puts some limits. Mac Pro customers are a bit more price insensitive than I thought a year ago, but I suspect the current Mac Pro prices are close to the limits ( e.g, kneecapping the entry Mac Pro with only 3 DIMMs instead of 4 and stripping off VRAM from the AMD Pro card base lines they modified for the D300/D500 ). Cost is on the table otherwise the configurations would look different.
I'm not sure cost is a huge thing for Apple. Driver development might be (for example, Crossfire GPUs have flat out not happened.) But I'm pretty sure they just want the fastest GPU that will fit their power profile.
Oddly Crossfire is enabled in Windows. Someone in the product management has bought into notion of "better gaming in Windows" buys some share worth putting work into. In OS X, no. It probably isn't worth the added complexity costs.
If a mix of GPU brands is the right move for the different tiers (maybe AMD is winning at mid-range, but Nvidia is at high end) they haven't been scared to mix and match too.
That is back in the now antiquated context of the GPU card work being done by other folks. Now that Apple has to incur the design of the cards. I don't see some convoluted product matrix happening at all. In every other embedded GPU design that Apple does there is one GPU vendor select per major design bake-off cycle. Those have all been single tracked.
When the R&D is largely punted to 3rd parties (either outsourced and/or after market opportunities)... sure. Apple will buy into that. Apple take on substantially higher inventory and return on investment risk.... not lately.
Good point, but even it just being a Windows only feature means Apple likely isn't inclined to factor it into any decisions.
The problem in the workstation market is that is is much smaller than the overall classic PC market ( personal computers excluding the tablets ). There are still substantial titles that carry weight that are Windows only because the Mac's sub 10% of the low millions workstation market is just to small to motivate ports to OS X. So BootCamp mode is a bit of a factor.
And as above... some yahoo thought Windows Crossfire was a "check the box" feature for the current Mac Pro. It isn't a prime factor, but if it is something "almost free" in the BootCamp support they have to do anyway then don't have to really push it into OS X either.
Metal would never work on the Mac unless Apple started making their own Mac GPUs. OpenGL already has enough trouble as a single standard as it is, and it's high level.
Mental/Mantle aren't a free pass long term. OpenGL is a more complicated stack but it deals with a boarder variety of hardware. I think that Metal/Mantle will lead to a flotsam of out of touch games over time. On iOS I don't think Apple cares. They will have taken their 30% cut of sales and will de-support the older hardware anyway over time.
Mantle has already bumped into the tip of the iceberg.
"... Because Tonga is based on a new GPU – and a newer version of GCN no less – the developers of Thief and Battlefield 4 have not had the opportunity to optimize their games for Tonga products. ..."
http://anandtech.com/show/8460/amd-radeon-r9-285-review/6
For the new card and non-aware software, Mantle isn't buying a whole lot in performance.
Gaming consoles don't change architectures every year. Perhaps there will be more shared gaming engine development over time but fast hardware development and low level APIs are in conflict over the long term from a maintenance and support perspective. How AMD makes that work long term will be interesting.