[emdog4]

Apple is waiting for the successor to the aging X99 Intel chipset. Intel has released the 100 series chipset but there are only max 20 PCIe lanes compared to the 40 max PCIe lanes possible with X99. this means the only possible configurations with the 100 series chipsets is x16,x4 or x8,x8,x4. With PCIe being the central bus with the Mac Pro it doesn't make sense for Apple to have released a new Mac Pro yet. The chipset technology in the current Mac Pro is still top of the line. Sure, you can get new processors with more cores and DDR4, but the number of PCIe lanes and memory speed/latency is optimal for the Mac Pro as as of now there is no better option for them to build a successor.

[bryanlarsen]

Intel's newest Xeon processors no longer work with the consumer chipsets such as X99, a Xeon class chipset must be used. If Intel was going to release a new chipset for Xeon, they would have released it with the E5 v4 last week.

It's quite possible Apple was waiting for E5 v4 and is still waiting for AMD Polaris or nVidia Pascal, though.

[walshemj]

Some people actually prefer the workstation class mb and there ones designed for use in place of x99

[Sanddancer]

This is where it gets complicated, because both the chipset and the processor have their own set of lanes. Skylake, and the 100 series, have 16 lanes from the processor, and up to 20 lanes from the chipset, with the chipset only able to aggregate in groups of four. The chips that use the x99/c61x chipsets have 28/40 lanes on the CPU, and have up to 8 lanes given by the chipset. So a hypothetical Broadwell-EP Mac Pro would not be stymied by the chipset, as it gets most of its PCI-e lanes from the processor already, and would see a significant performance boost compared to the current processors, given that the high end chip from then is about middle of the road in Intel's current lineup.

[pier25]

Sounds plausible, but why not even release an upgrade to the outdated GPUs or the CPU?

The current 15'' rMBP is faster in single core operations...

[extra88]

As a rule, don't buy a Mac Pro when you're doing single core operations. It's often not worth the money even for multi-core, multi-core plus using the GPUs is when it's the right pick. I'm referring to choosing a Mac, not comparing Macs & PCs.

[rarepostinlurkr]

Or they've decided to cut out of that market segment entirely. Will be interesting to see what unfolds.