USB Ports, Adapters

The adaptor is called a USB hub, and it has been around since USB 1.0.

If the hub itself is not powered, the power available to the hub has to be shared among all devices connected to the hub. How much that is, depends on the USB specification. Not all USB devices take power from the connection.

If the hub is powered, check the power specifications for the hub itself. These will vary quite a bit with product.

Hubs always have to share the USB bandwidth, whatever that is, among connected devices. USB port, device and hub specifications, connectors, cables can all impose limits on bandwidth.

From the OP

Do each of these additional new ports have the same power/capability as the original port that's being split four ways?

And yes data use has to be managed, I mentioned that

It's funny... So many of the responses in this thread were only concerned with power draw. My concern when daisy-chaining devices is data bandwidth. You can plug a ridiculous quantity of devices in to a single root hub, and with self-powered splitters and hubs, power is not a real issue. But the amount of data that can travel through that hub is still limited by how fast the root hub can communicate.

It's like throwing a party at your house. If you have four or five people over, you can follow the conversation pretty easily. If you have forty guests, and they're all in the same room, nobody can follow all the conversation and it gets loud quickly. The solution is to put smaller groups in different rooms. Maybe split up your "chatterbox" guests so that there's only one of them per room with some quieter people.

OP here...thanks to all for your answers.

There is some confusion of the issue at least in regards to my statements
I don't use the pc as a phone charger
But when I connect my cellphone to pc to transfer pictures, or videos, or to cable tether for internet, the phone automatically draws power to charge the battery, so it is using the USB port, and there is no way of stopping that
And your phone will do the same thing if and when you transfer pictures etc..
If there are other devices like a memory stick or portable USB drive on that port using shared adapter, then THAT power has to be shared among all of them and it's Not enough power
Same thing happens when I plug in the wife's tablet to transfer her country music video files and shows from the laptop to the tablet
An adapter port is a great place for items that have their own power , printer scanner etc..and are not all used at the same time
Consequently I see no problem with printer mouse and keyboard on a shared data self powered port adapter
Think about it, if your using the mouse you aren't typing on the keyboard, and if you are typing you are not scrolling the mouse or printing
Mouse and keyboard are low intensity items, lots of CPU cycles happen between key strokes even if you are a speed typist
I use individual USB ports for my various external hard drives and video capture connections, my printer spends 95 percent of its time unplugged turned off
Data transfer to external drives, USB sticks, and scanner input, is the heavy traffic that needs open data lines, and fill USB port power
Mouse and keyboard, are like comparing a smart car, to high speed commuter rail traffic

jerseyjim wrote:
Gee....things is so complicated now.Why? I have my Belkin 4 USB port adapter into one laptop USB....my wireless mouse into another and my hardwired keyboard into the third. All work fine. My cell phone came with a house charger...and I bought a 12V charger for the car/motorhome. My Tablet has it's own house charger...2.0, 3.0 (for speed?) USB ports and colors? Don't know. Everything works fine. Of course I use this laptop strictly for pleasure...not business.
Maybe I compartmentalize too much...........

I would tend to aggree with your point.

But for some strange odd reason, folks seem to think a PC should charge a cellphone and tablet..

Cellphones and tablets come with their own wall chargers AND with a simple high current 12V cig to USB charger can easily charge directly from a 12V battery.

Modern cellphones and tablets are able to "adapt" to the max charging current of a computer USB port but in doing so will take forever to charge those devices.

The reason.. Well smart cellphones and tablets ARE designed to charge the fastest with 2A-2.4A at 5V.

Plugging a cellphone or tablet into a PC USB port will result in only charging at a max rate of 500 ma, This results in a charge time of at least if not more than 5 times longer than if you used to proper 2.4A charger.

So if your cellphone or tablet took 2hrs to charge with the proper 2.4A charger it will take 10 or more hrs to charge with a 500 ma USB port.

Computer USB ports were NEVER designed to be a "charger" for cellphones or tablets..

By the way, you CAN "blow out" the 5V part of a computer USB port.. Pretty much TRASHES that port and if your laptop has one USB port you now have a door stop. A PC USB port is a rather expensive charger..

Buy the proper 12V to USB charger for those devices, you can get 2.4A 12V to 5V USB charger for $5 now days..

Do the expansion ports have the same power capibility.. Yes and no.

If it's a simple 4 port hub.. then no the power of the computer's port is split,

But if it is a POWERED port.. Then the power of the wall wart is sent to the devices, the computer just sends a signal (Very little power) and 4 ports.. Try the item in this link

24 port hub

Gee....things is so complicated now.Why? I have my Belkin 4 USB port adapter into one laptop USB....my wireless mouse into another and my hardwired keyboard into the third. All work fine. My cell phone came with a house charger...and I bought a 12V charger for the car/motorhome. My Tablet has it's own house charger...2.0, 3.0 (for speed?) USB ports and colors? Don't know. Everything works fine. Of course I use this laptop strictly for pleasure...not business.
Maybe I compartmentalize too much...........

900ma, you're talking about a charging port when you talk about 1500ma.

I can't make sense of the rest of it unless you restate it--on one hand you seem to be talking about logical root, the next a physcial header, and intermittently bouncing back to USB 2.0.

greenrvgreen wrote:
If the OP's computer is more than five years old, he may have USB 2.0 ports, not USB 3.0. A quick way to tell is to look at the sockets. If the plastic inside the socket is blue, it is USB 3.0; if it is white, it is USB 2.0. This will put a limit on both the speed and the power available, as said.

Just to confuse things, most laptop mfrs use USB splitters on each side of the laptop, so that two ports on each side is actually only two USB ports total--again limiting bandwidth and available power.

The simplest USB 3.0 4-port UNpowered hubs cost around ten bucks and do a good job. Even if you have USB 2.0, I recommend you get a 3.0 splitter, such as made by Anker or Sabrent.

Any device that has its own power supply can run from an UNpowered USB hub. Sometimes they can benefit from a powered hub. I don't know why but I have a LOT of experience trying to get these stupid things to work together.

Sometimes a powered hub that's UNDER powered can makes things worse, even for powered devices. I have thrown away several UNDER powered USB hubs because I didn't read the specs carefully. What happens is that the USB controllers mistakenly think a device has been removed and disconnect it, sending my blood pressure skyrocketing.

If the OP has several devices that require power and the requirements exceed the 900ma PER SIDE, NOT PER SOCKET (because they're likely connected), then I highly recommend the Anker 7-port 35-watt USB 3.0 hub, about $50. Unfortunately it is the size and shape of a cartoon of cigarette packs, but it does the job well and saves my blood pressure.

Umm. no.

Your PC CONTAINS what is known as a "ROOT HUB", this is NOT a "splitter" but an ADDRESSABLE USB PORT HUB.


On the first page of this thread, poster Stefonius mentioned this..

"The port on your laptop is technically a "root hub", and can address and manage up to 127 simultaneously connected devices at once. The thing to consider is how you split up the available power and data bandwidth. Power is not a problem if you use hubs that are self-powered. As for data, I would not plug an external hard drive or flash drive into the same root hub as my mouse, keyboard, etc. "




Typically every PC is equipped with at least two or more ROOT HUBS.

Each ROOT HUB typically contains FOUR USB PORTS.

USB1 and USB2 speed ports ARE capable of supplying FIVE HUNDRED MILLIAMPS (500ma) TO EACH USB PORT.

USB3 speed ports can capable of up to 1,500 ma but that spec is not set in stone at this time so your mileage may vary..

The external USB port expanders you buy are ALSO ROOT HUBS and those can be "self powered" (IE gets power from the PC) or externally powered (uses external power supply).

The self powered ROOT HUBS MUST "SHARE" the available 500 ma between all it's ports.

An external POWERED ROOT HUB can supply a full 500 ma TO EACH OF IT'S OWN PORTS..