What makes a workstation, anyway? Exotic graphics hardware? (I thought you could get Apple to build you a Mac Pro with a stack of Quadros, although I just checked the Apple Store and that doesn't seem to be an option anymore, so maybe you've got a point there.) A RISC processor? (Good luck with that, these days.)
If the Mac Pro is insufficiently workstation-y for you, how about the Cray CX-1 family, which last I checked is still in production?
A Mac Pro is just an overgrown PC, much like any Intel server you can get from Dell. It's pretty and classy and, while it runs a real Unix, the whole platform was really designed to run Windows, much like every Intel box has been for a long time. It was a compromise made when Apple switched away from PowerPCs.
What made a Unix workstation something unique is that it was built not to run legacy software (I bet the latest Dell can still boot MS-DOS 3.3) but to be the fastest possible machine that given amount of money could buy. That involved, of course, custom graphics hardware, weird disk controllers and exotic buses with hardware-assisted everything. It's a shame most people never experienced this and, for the time being (can you imagine someone building a desktop computer that cannot run Windows?), won't.
As for the CX-1, it's a cluster of PCs in a deskside package. Lame. Seymour would never approve it.
Today the fastest possible machine that given amount of money can buy is an x86 PC. The cost of the backwards compatibility crap is more than subsidized by the huge economy of scale. Removing DOS/Windows support would actually cost money and would make no performance difference.
In particular, the fastest possible machines that any amount of money can buy tend to be, these days, basically just piles of x86 PCs. http://www.top500.org/lists/2009/11
Also, "the fastest possible machine that given amount of money can buy" is an x86 PC precisely because there are no more Unix workstation manufacturers left.
Unix workstations were built to run Unix. A Mac pro is essentially a PC. It boots through EFI and is capable of running OSX, but all of the parts of a PC are still there. The proof is that it runs Windows.
The difference looks subtle now, when every desktop computer is essentially the same. For those who lived through this, like the writer of the original article, it was blatantly obvious.
Well it's a question of artificial ontology, isn't it? I mean, it'd be awfully tough to legally define what's a "UNIX workstation" and what's a mere "PC". Plenty of UNIX workstations have run Windows in varying capacities, so that can't really be it.
I'd think to capture the "spirit" you'd start with something like "UNIX workstation: a primarily single-user computing system designed by a vendor to primarily run that same vendor's UNIX operating system, an operating system designed exclusively to be run on that vendor's computing systems and which can't easily be run on other vendors systems". That sounds a lot like the business Apple's in (and which apparently nobody else is anymore).
