What CAN'T I do with the Thunderbolt 3 ports on the right side of the 13" MacBook Pro?

[justinf77]

There was an article on MacRumors stating how on the 13" Touch Bar MacBook Pro, only the left side ports have full Thunderbolt 3 performance. The thing is, I'm not exactly sure what this means. Will will I NOT be able to do using the ports on the right side?

 

[chunology]

The right side only has reduced PCI Express bandwidth, which means that you should connect PCIe components to the left side of the Mac (typically video components/monitors). Plugging in USB-C thumb drives, etc should be fine.

 

[Deanster]

Really only 4K/5K monitors need the full performance of TB3 at the moment.

There's no consumer storage in the world that can accept data as fast as a half-speed (single PCIe stream) TB3 port can send it, at least that I'm aware of.

 

[Chancha]

In the future there may be video capture devices, multiple SSD RAID array etc that demands full TB3 bandwidth. But as of now the only thing close are HiDPI 10 bit displays, multiples of them through one cable, and those such as the LG 5K at 60Hz are limited by the Mac's GPU ability anyway, therefore the 13" without Radeon cannot drive two of them.

 

[Samuelsan2001]

There was an article on MacRumors stating how on the 13" Touch Bar MacBook Pro, only the left side ports have full Thunderbolt 3 performance. The thing is, I'm not exactly sure what this means. Will will I NOT be able to do using the ports on the right side?

Running a 5k screen over one cable! That's it the other 2 are still thunderbolt 2 bandwidth and can do everything that the last thunderbolt or USB A could do.

 

[killawat]

There's no consumer storage in the world that can accept data as fast as a half-speed (single PCIe stream) TB3 port can send it, at least that I'm aware of.

I know you say consumer but really, I think vendors will come out with SSD based solutions soon for cheap.
LaCie Big 12 2600 MB/s plus 2 4k screens or a single 5k screen can saturate the bus today.

 

[Hyloba]

I guess you could keep charging your MBP on the right side, as well with a small dock for usb and sd card, and the heavy stuff on the left side.

 

[justinf77]

Got it, thanks! So it seems like for my purposes I'll just have to plug in the monitor on the left side but other than that it will make no difference.

 

[curmudgeonette]

Got it, thanks! So it seems like for my purposes I'll just have to plug in the monitor on the left side but other than that it will make no difference.

Your monitor would be a good use of a right side port.

The "reduced bandwidth" likely means that the Thunderbolt controller for the right side shares PCI bandwidth (via a PCI switch) with something else. Perhaps with the SSD, or Bluetooth, or Wifi. Or maybe it is connected via slower speed PCI lanes on the PCH.

Displayport video won't be affected by reduced PCI bandwidth. It has its own routing between the GPU and the Thunderbolt controller.

 

[justinf77]

Your monitor would be a good use of a right side port.

The "reduced bandwidth" likely means that the Thunderbolt controller for the right side shares PCI bandwidth (via a PCI switch) with something else. Perhaps with the SSD, or Bluetooth, or Wifi. Or maybe it is connected via slower speed PCI lanes on the PCH.

Displayport video won't be affected by reduced PCI bandwidth. It has its own routing between the GPU and the Thunderbolt controller.

This is helpful, thanks! So for a DisplayPort monitor, I can plug it into the right side, but if I happen to buy the new 5K LG monitor from Apple, I assume that would need to be plugged in to the left side?