Learning USB C

USB Type-C is a very complex connector. Attempting to be a jack of all trades and the master of all, it certainly has a potential to be the one. Apple manifested this potential by removing all other ports (but the 3.5mm phone jack) from MacBooks two years ago. But the potential is one thing and the reality of the transition and the learning curve is the other.

I have been using the 2018 15" MacBook (with Windows 10 as the primary OS) for a couple of weeks now and the Type-C reality is still far from what it could / should be.

I learned a while ago that the quality of cables mattered the most. The first surprise was that Type-C does not automatically mean USB 3 (or 3.1) in terms of speed. Majority of "ordinary" Type-C cables can only do USB 2 speeds (480Mbps), which is 10x slower than USB 3.0 (5Gbps) and 20x slower than USB 3.1. To get decent speed with a peripheral, buy only cables marked "SS" (SuperSpeed - 5Gbps) or SS10 (10Gbps). Everything else will crawl.

Type-C connector can do USB PD (Power Delivery - up to 100W with 5A at 20V), which Apple has been prominently using for all MacBooks now. The most power hungry 15" MBP comes with an 87W power brick and it is hard to believe this tiny connector can handle that much current without heating and burning the contacts. Hence the quality again - do not skimp on cheap cables. It is convenient to use just a single power supply to charge a laptop, a phone (BlackBerry in my case) and other accessories, like an iPad.

Unfortunately iPads still have the [old] lightning port and a Type-C - to - Lightning cable is required. And there is only ONE that works (after the iOS 11.3 update) - the original from Apple. With the 11.3 update Apple bricked all other Type-C-to-Lightning cables and adapters. Not sure why, but this is the fact. They must have discovered some dangerous incompatibility with USB PD, or how it is handled by iOS devices. To the extent that the Apple cable has a USB hub built in the USB connector. Putting a hub in a connector normally does not make sense unless you want to isolate (or mediate) protocol negotiation between devices on both ends of the cable. Apple's cable does that isolation / mediation: when you plug the cable to the computer Windows plays a sound and a new USB hub appears in the device manager (this normally never happens when plugging just one end of a cable). So this, and only this cable can be used to charge a lightning iOS device from a Type-C power source. Ugly.

Now as the BlackBerry charges from the Apple power brick, it seems straightforward it should be able to charge from the MacBook - using a straight C-to-C cable, right? Wrong! It does not. But daisy-chaining a C-to-A and the A-to-C converters solves the problem. Yet another unexpected incompatibility...

In another way to see the problem you may look at the two Type-C chargers by Anker: the 18W and the 27W one. Identical in size, the latter is $2 more expensive. And looking at the specs, you can see that the first one provides "USB-C Output: (PDO) 5V 3A, 9V 2A; (PPS) 3V–5.9V 3A, 6V–11V 2A" while the second one has "USB-C Output: (PDO) 5V 3A, 9V 3A, 12V 2.25A, 15V 1.8A, 20V 1.35A; (PPS) 3–11V 3A". IOW by spending $2 more, your charger will do 12V, 15V and 20V: voltages that may be required by some devices, or at least will charge them faster.

It seems that the Type-C standard has too many optional requirements. Options are fine when there is a clear way to communicate to the user if they are not supported and what are the consequences. But if, for example, the super speed requirement is optional for a cable that connects two super speed devices of if some voltages are optional for a power source while the end device is not able to cry loud that it cannot be charged, the UX suffers. And with the UX suffers the reputation of the standard. We may just hope all that will ultimately be solved, but at least for now, Type-C is still work in progress and a steep learning curve for both vendors and users.