Since the new Mac Pro has only one CPU, the natural thought might be: how do high-end users group them together with suitably fast I/O for high-performance clustered computing (e.g., video or scientific processing)? For example, a 10-gigabit NAS, or fast inter-process communication over the network.
With so many performance innovations in the new model, it’s too bad that 10-gigabit ethernet is not built-in to the new trashcan Mac pro (and with no slots, no gigabit card can be installed internally it seems). Apple has always tended to move things like this forward (but the answer might be that Thunderbolt is the answer). Maybe 10 Gbps ethernet will never go mainstream (ditto for Thunderbolt?).
Why does it matter? Because 10-gigabit ethernet provides enough bandwidth to transfer big data sets for at least some clustered compute-intensive environments.
Still, the new Mac Pro form factor (cylinder) makes it nearly the worst possible shape for space efficiency (volume) for conventional rack-mount environments; such users might as well choose cheap Linux boxes instead, although the two high-performance GPUs might be attractive.
Don H writes:
I've written before (and you even posted my thoughts) about 10G Ethernet, lamenting that no one outside of the data center has adopted it yet. It's one of the first specs I check for when scanning through PC/server reviews at Anandtech, so I'm ready to notice if/when it finally makes it onto a motherboard (and so far it hasn't, as far as I can tell).
Unfortunately, the ports on the machine are still only half of the picture. We also need affordable 10G switches, which likewise remain nonexistent. Combined, both parts cause the old chicken/egg conundrum of market demand needed to justify each side of the equation. (There are no affordable switches yet because there aren't enough machines to use them, and vice-versa.) Also keep in mind that 10G Ethernet requires yet another cable upgrade for many installations, so that adds even more to the cost for a lot of people.
I don't know the price delta between a 1G and 10G Ethernet port on a client motherboard (there simply are no data points, and I'm not an OEM purchaser), but 10G add-in cards are multiple hundreds of dollars, versus $15-$50 for 1G cards. Obviously a lot of that can be attributed to lack of volume, but even still it's a pretty dear price to pay for most people who won't have the rest of the infrastructure in place to take advantage of it.
While Apple's abandonment of PCI card expansion thwarts most third-party solutions, there is one glimmer of hope. The latest Thunderbolt spec allows for 20Gbps throughput, which could comfortably handle a 10G Ethernet adapter/dongle. I feel the same way as you about the sheer messiness of external adapters versus internal expansion, but an enterprising third party might eventually create an all-in-on expansion dock that includes 10G Ethernet in the mix (similar to today's [overpriced] Thunderbolt docks). And of course, Apple and everyone else will eventually switch over to native 10G Ethernet ports when the time is right, but alas in 2013 the industry still isn't there yet.
MPG: Thunderbolt is presumably the route, built-in ports would have been better.
I don’t see the gear and cabling costs as real issues; any outfit doing cluster computing that can benefit from 10Gbps can by definition can afford the costs (in context of multiple systems each costing $4K - $10K or more). Ordinary users will do fine with Gigabit ethernet, high-end compute-cluster installations are not cheap in any case.
On the other hand, there are small workgroups utilizing 2/3/4/5 Mac Pros that could benefit by sharing a fast and capacious NAS device: gigabit is much too slow for big Photoshop files. In such cases, perhaps a shared Thunderbolt NAS might be an answer, bypassing ethernet entirely.
It's important to note that 10GE ports would required 4 PCIe lanes dedicated to them. Is that really the best use of precious PCIe lanes in the Mac Pro? Of course not.
Not everyone wants or needs 10GE. By offering three TB controllers each utilizing 4 PCIe lanes, users can better adapt it to their specific needs. I'd much rather have it the way it is than have Apple deciding for me how those PCIe lanes should be allocated. Be careful what you wish for. :)
MPG: 10 gigabits per second = 1.25 gigabytes per second, hardly a strain for the PCIe bus. A single Thunderbolt v2 port offers 20 Gbps (20 gigabits per second) bidirectionally, twice the speed of 10 GBps ethernet. My understanding is that there is some loss of bandwidth from 10/8 bit encoding, but that is a nit.