Re:Linux on the Mac – state of the union
by TazeTSchnitzel on Monday December 12, 2016 @11:34AM
(#13159326)
There's 4 40Gbit/s ports, but their total bandwidth is not 160Gbit/s. IIRC, the ports on the right side of the machine have less total bandwidth because of how they're connected, for example.
That is correct. The Thunderbolt controller has two DisplayPort sink ports which are wired to the GPU, in addition to the PCIe 3.0 4x interface which goes to a root port in the CPU. So to actually max out the 40 Gbit/s, you need to drive external displays and also max out the PCIe 3.0 4x interface. Which is another way to say that 8 Gbit/s are reserved for DisplayPort.
Re:Linux on the Mac – state of the union
by skynetv2 on Monday December 12, 2016 @08:16AM
(#13157809)
Can you run network stack at 40 Gbps on those ports?
Yes, but as stated in the article only on macOS or Linux on non-Macs. Not with Linux on Macs unfortunately. Someone needs to scrutinize the Intel-developed code for non-Macs, figure out how to port it to Andreas Noever's driver, and fill in the missing parts by reversing the macOS driver.
Also, the Alpine Ridge controllers are attached with PCIe 3.0 4x lanes, that's 31.504 GBit/s, so you can't exhaust the available bandwidth fully.
Or let's say you want to quickly set up a Hadoop cluster to crunch some data.
Five machines is certainly small as HPC clusters go, and in reality you'll probably have to cap this to four machines because you need one port to attach to a power socket if you need the cluster for more than 2-3 hours. Nevertheless the 4x 40 GBit/s Thunderbolt ports offer some really interesting possibilities, and I'm not aware of any other portable machine that has this right now.