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Ever notice all those gold contacts on cables and connectors?

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When whether it's a USB drive, an HDMI cable, or a graphics card,

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they have a ton of those little pins on there. But why do they need so many?

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Let's start out with possibly the most straightforward reason of all.

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Power. Putting an electrical connection and a data connection on the same contact would cause interference.

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So most modern digital connectors separate those onto different pins.

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And then you have the fact that current needs to return via a ground connection,

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meaning you need at least two connectors for power, which you see in USB-A connectors, for example.

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But having tiny pins means you can only put so much current through them.

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Think about how when you go and buy an extension cable, the larger ones are rated for more power than the smaller ones.

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It works similarly with your electronics. So devices that need relatively large amounts of power

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often spread out their power delivery across many contacts.

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A great example of this is pins on a CPU. Modern processors have over a thousand pins,

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many of which are dedicated to power delivery. With higher-end CPUs now drawing over 150 watts at load,

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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

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through just one little pin. He's only one pin, John!

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Speaking of power, some connectors have additional pins to accommodate multiple voltages.

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You can see this in the standard 24-pin power connector for computer motherboards,

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which has to provide 12V, 5V, and 3.3V power.

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And while most components these days run off 12V, the other voltages are still supported for any components

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that still need to get the lower voltages directly from the power supply.

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But there are plenty of other reasons for all those pins being there besides just power.

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Part of the reason we can send so much data at once these days

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is because of something called differential signaling.

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Basically, each data signal is sent using two pins instead of one,

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and each signal is basically the same, except one is positive and one is negative,

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as you can see on this illustration. This has a few advantages over just using one pin to send a signal.

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It can resist interference better and operates using less overall power,

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meaning that the connection can operate at higher frequencies,

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meaning more data per second. You can pretty clearly see the two differential signaling contacts on this USB connector.

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Higher speed connections will often spread out their bandwidth over multiple differential pairs

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in order to increase the overall amount of data that can be sent per second.

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This is part of the reason USB-C has more contacts than older USB-A connectors,

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and also makes up the vast majority of contacts on a PCI Express X16 graphics card.

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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.

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Some connectors dedicate a pin to a clock,

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a separate signal that keeps the flow of data synchronized.

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Others might have a pin to enable some kind of special functionality,

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such as consumer electronics control or CEC on HDMI.

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CEC is what allows you to control something like the volume on your sound bar

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through your TV remote, and some pins simply serve as shields for adjacent pins to prevent interference,

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or as presence detectors simply to let the system know that a device is connected.

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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,

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as disappointing as that is. Go watch this video next to find out more about why CPUs specifically have so many pins

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and why their sockets keep on changing. Why?

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But you haven't clicked away yet, so I want to say hey, thanks for watching.

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Like the video if you liked it, dislike it if you disliked it. Check out our other videos, comment below with video suggestions.

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