Question Motherboard 3.2 to 2.0 adapter

Feb 20, 2021
Hi, I was wondering if there was a motherboard 3.2 usb to 2.0 usb adapter. I have 2 usb 2.0 and 2 usb 3.2 and I'm using 1 of the usb 3.2 and need more 2.0 ports because I ran out. I can only find 3.0 to 2.0 and I'd rather not risk compatibility. I hope you can help with this.


Actually, the USB 3.2 system was designed with backwards compatibility. Physically the common Type A sockets and connectors for both systems are very similar so you CAN plug a USB 2 device and cable into a USB 3.2 socket, etc. and it WILL work. The difference is that the USB 3.2 system has five extra electrical lines and contacts that are used when a USB 3.2 device / cable are used. But if you plug in a USB 2 cable, then only those basic four lines are used and the system adapts to that device for that particular USB 3.2 socket / port.

That said, such a connection is a real under-use of the USB 3.2 port's abilities. So the suggestion above to get a USB 3.2 HUB is a good one. When you do that, all of the devices plugged into the Hub share the bandwidth of the single USB 3.2 port the Hub is plugged into. So especially if you are plugging in several USB 2 low-speed devices on the high-speed USB 3.2 Hub, the high bandwidth of the 3.2 system can handle all of the USB 2 units easily. It's like having many new USB 2 low-speed ports, but using only one real USB 3.2 port to do it.

When buying a HUB, pay attention to power and get one that comes with its own power supply module or "wall wart". The original USB 2 port can provide a 5 VDC power supply to a connected device at up to 0.5 A max current draw. The newer USB 3.2 ports can supply that voltage at up to 0.9 A current, which helps many devices. But when using a Hub, ALL of the devices on that Hub share that power source and its limit. So it is ideal to have the HUB have its own power supply module so that the HUB can supply that power to EACH of its output ports, and the host computer's port limit does not apply. So get a Hub with that module AND pay attention to the power supply module's ratings.

That gets tricky. First item is that many now come with "Charging Ports" as well as data -only ports. Some of these are for changing only, and some can do both functions, so look for that detail. What is unique about them is that a Charging Port can supply that same 5 VDC at a higher max current to charge devices faster - higher than the standard USB 3.2 limit of 0.9 A per port. I'll come back to that later. But for now, let us ignore any Charging Port and look only at the data ports on the Hub. Ideally, each of those should get enough power from the power supply module to allow it to output up to the max 0.9 A per port at 5 VDC. And here's where the next tricky part comes in. The power supply modules often put out 12 VDC,and the Hub alters that to 5 VDC. So how to compare? You must use the WATTS ratings. 5 VDC at 0.9 A per port is 4.5 W per port. Multiply by the number of data ports, and you know the max power in WATTS that the Hub should be able to put out, and thus must have from the power supply module. THEN look at the PS's rating. Often that is given already in Watts. If not, Watts = Volts x Amps. So if the rating is 12 VDC at 3.0 A max, then that's 36 W, enough to supply up to 8 ports at 4.5 W per data port.

Next step is to add in the requirements of the Charging Ports. They will be specified as having higher Amp limits, often 2 to 5 times as much as a standard data port. Calculate the Watts for each such port, and add that to the power requirements of the data ports to get the total power in Watts for the Hub. Now we run up against reality. You almost never find a Hub supplied with a Power Module that does supply that max Watts. This is because one almost never uses all of the ports at their max loads simultaneously. Even it many things are plugged into Hub ports, several of them are usually idle much of the time. So to avoid over-supplying power to the Hub and thus save money, the Power Module is rated less than the theoretical max load. If the rating is 70% or more of the max load, that should be just fine. If it's 50% or less, I'd worry a bit. Also take into account that you may NOT plan to use those high-current Charging Ports and thus can expect a lower max requirement from the Power Module. Then one last trick. If you are considering several Hubs, sometimes it's wide to buy one with more ports than you need, because that larger one comes with a higher-capacity Power Module.

A further note. USB 3.2 now has three variants. 3.2 Gen 1 can do up to 5 Gb/s (about ten times what USB 2 could do) data transfer rate, and works with both the older Type A and the newer and smaller Type C ports and cables. Most USB 3 Hubs are designed for this version. USB 3.2 Gen2 doubles that data speed max to 10 Gb/s, which is faster than any one device on the market can do, but might be an advantage if you are using several USB 3.1 or 3.2 devices connected to that Hub to share that higher bandwidth. It can work with the Type A connectors, but use of the newer Type C connector is recommended for reliability at high speed. Few Hubs are rated for this performance level but some are, so IF you want that watch carefully for the claims made by its maker. USB 3.2 Gen 2x2 is the latest, rated for up to 20 Gb/s. It is available only from a special Type E mobo header on mobos so equipped, and can only use the Type C connector from the case to the Hub. You probably do not have this, and may not need anything like that total data rate for many years!
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