WEBVTT 00:00:00.000 --> 00:00:03.360 Ever notice all those gold contacts on cables and connectors? 00:00:03.360 --> 00:00:07.400 When whether it's a USB drive, an HDMI cable, or a graphics card, 00:00:07.400 --> 00:00:11.200 they have a ton of those little pins on there. But why do they need so many? 00:00:11.200 --> 00:00:14.500 Let's start out with possibly the most straightforward reason of all. 00:00:14.500 --> 00:00:21.200 Power. Putting an electrical connection and a data connection on the same contact would cause interference. 00:00:21.200 --> 00:00:25.100 So most modern digital connectors separate those onto different pins. 00:00:25.100 --> 00:00:29.200 And then you have the fact that current needs to return via a ground connection, 00:00:29.200 --> 00:00:34.600 meaning you need at least two connectors for power, which you see in USB-A connectors, for example. 00:00:34.600 --> 00:00:39.000 But having tiny pins means you can only put so much current through them. 00:00:39.000 --> 00:00:45.000 Think about how when you go and buy an extension cable, the larger ones are rated for more power than the smaller ones. 00:00:45.000 --> 00:00:49.600 It works similarly with your electronics. So devices that need relatively large amounts of power 00:00:49.600 --> 00:00:53.200 often spread out their power delivery across many contacts. 00:00:53.200 --> 00:00:58.800 A great example of this is pins on a CPU. Modern processors have over a thousand pins, 00:00:58.800 --> 00:01:05.100 many of which are dedicated to power delivery. With higher-end CPUs now drawing over 150 watts at load, 00:01:05.100 --> 00:01:11.400 roughly the same as a 75-inch TV, it isn't hard to understand why you don't want to put all of that power 00:01:11.400 --> 00:01:15.700 through just one little pin. He's only one pin, John! 00:01:15.700 --> 00:01:21.100 Speaking of power, some connectors have additional pins to accommodate multiple voltages. 00:01:21.100 --> 00:01:25.300 You can see this in the standard 24-pin power connector for computer motherboards, 00:01:25.300 --> 00:01:29.800 which has to provide 12V, 5V, and 3.3V power. 00:01:29.800 --> 00:01:35.700 And while most components these days run off 12V, the other voltages are still supported for any components 00:01:35.700 --> 00:01:39.200 that still need to get the lower voltages directly from the power supply. 00:01:39.200 --> 00:01:43.600 But there are plenty of other reasons for all those pins being there besides just power. 00:01:43.600 --> 00:01:47.200 Part of the reason we can send so much data at once these days 00:01:47.200 --> 00:01:51.100 is because of something called differential signaling. 00:01:51.600 --> 00:01:55.800 Basically, each data signal is sent using two pins instead of one, 00:01:55.800 --> 00:02:01.300 and each signal is basically the same, except one is positive and one is negative, 00:02:01.300 --> 00:02:07.000 as you can see on this illustration. This has a few advantages over just using one pin to send a signal. 00:02:07.000 --> 00:02:11.000 It can resist interference better and operates using less overall power, 00:02:11.000 --> 00:02:14.200 meaning that the connection can operate at higher frequencies, 00:02:14.200 --> 00:02:21.500 meaning more data per second. You can pretty clearly see the two differential signaling contacts on this USB connector. 00:02:21.500 --> 00:02:26.600 Higher speed connections will often spread out their bandwidth over multiple differential pairs 00:02:26.600 --> 00:02:30.600 in order to increase the overall amount of data that can be sent per second. 00:02:30.600 --> 00:02:36.000 This is part of the reason USB-C has more contacts than older USB-A connectors, 00:02:36.000 --> 00:02:41.700 and also makes up the vast majority of contacts on a PCI Express X16 graphics card. 00:02:41.700 --> 00:02:48.200 And there are some other functions that extra pins perform outside of ensuring data gets from point A to point B as quickly as possible. 00:02:48.200 --> 00:02:51.300 Some connectors dedicate a pin to a clock, 00:02:51.300 --> 00:02:54.600 a separate signal that keeps the flow of data synchronized. 00:02:54.600 --> 00:02:58.100 Others might have a pin to enable some kind of special functionality, 00:02:58.100 --> 00:03:02.600 such as consumer electronics control or CEC on HDMI. 00:03:02.600 --> 00:03:06.400 CEC is what allows you to control something like the volume on your sound bar 00:03:06.400 --> 00:03:12.200 through your TV remote, and some pins simply serve as shields for adjacent pins to prevent interference, 00:03:12.200 --> 00:03:16.700 or as presence detectors simply to let the system know that a device is connected. 00:03:16.700 --> 00:03:24.600 So contrary to popular belief, engineers didn't put all these pins there just because they were really into making electronics look like fancy gold combs, 00:03:24.600 --> 00:03:31.200 as disappointing as that is. Go watch this video next to find out more about why CPUs specifically have so many pins 00:03:31.200 --> 00:03:34.800 and why their sockets keep on changing. Why? 00:03:34.800 --> 00:03:37.900 But you haven't clicked away yet, so I want to say hey, thanks for watching. 00:03:37.900 --> 00:03:43.200 Like the video if you liked it, dislike it if you disliked it. Check out our other videos, comment below with video suggestions. 00:03:43.200 --> 00:03:47.400 What are you thinking about? What do you want us to talk about? And don't then don't forget to subscribe and follow. 00:03:47.400 --> 00:03:50.400 It's just, you got a list. I gave you a list to do.