What is difference between front and rear USB ports?

Hardware geeks: What is the difference between the USB ports in the front of a PC and the ones in the back of the PC?

The reason I ask is b/c the install intructions that came with an external Seagate HD specifically stated to plug the USB cable into a rear USB port, or else damage to the HD could occur.

I'm sure it depends on the machine you have. I think sometimes there are both USB 1 and USB 2 ports, with probably the front ones USB 1.

djohnsto77 is right. USB 2 is faster (something to do with the cables and shielding) so it sounds like your new drive requires USB1. Is that true?

Anything made to work in a USB2 will also work in a USB1, but not vice versa.

What computer do you have and we can look it up.

Edit: Sorry, I had thiem switched around and had to edit.


[edit on 19-3-2007 by Benevolent Heretic]

So, are you saying that some PC's have both USB 1.1 and USB 2.0 ports in them? That sounds like a strange way to design a machine. Mine are all 2.0, according to the control panel. I would assume a disk drive would want the faster ports, which apparently are on the rear of the machine.

The install instructions actually say that plugging the drive into a front USB port will cause it to malfunction, which covers a wide array of problems, including speed-related ones.

Anyway, the drive works fine plugged into the back. I was just curious about the warning. Now I've learned something.

Thanks. folks.

Just to add, as silly as any instructions may seem its best to comply with them as to not void warranty.

Originally posted by jsobecky
The install instructions actually say that plugging the drive into a front USB port will cause it to malfunction, which covers a wide array of problems, including speed-related ones.

oh wow this is a good question as I wondered why I have 5 usb ports, 4 at the back and one at the front. I have never used the one at the front.
Why would they put a usb at the front if it malfunctions?

I would like to use it for my phone as it would be easier to transfer data plugging it in the front rather than dickering around the back of it.

Originally posted by NJE777

Originally posted by jsobecky
The install instructions actually say that plugging the drive into a front USB port will cause it to malfunction, which covers a wide array of problems, including speed-related ones.

oh wow this is a good question as I wondered why I have 5 usb ports, 4 at the back and one at the front. I have never used the one at the front.
Why would they put a usb at the front if it malfunctions?

I would like to use it for my phone as it would be easier to transfer data plugging it in the front rather than dickering around the back of it.

They are just the same. I hardly have heard of any motherboard using different USB hubs, its pretty strange.

mixing 2.0 and 1.1 would actually cost more since they would need to incorporate both hub technologies which is funny.

[edit on 19-3-2007 by Selmer2]

Originally posted by Selmer2
They are just the same. I hardly have heard of any motherboard using different USB hubs, its pretty strange.

They say that people look like their animals....cars also signify a person...and a pc is like the person's mind. Hmmm, pretty strange sounds about right for me lol

I am going to plug my phone into it and see what happens. If I am not online for a while then you will know its malfunctioned!

It depends.

Newer PC's, made after 2005, no longer have USB 1.1, and they are all USB 2.0 . So the only difference is that they are in a different place.


Older PC's, made before 2005, have a combination of USB 1.1 and 2.0. the USB 1.1 ports are in the front, for easy connection to low power devices, such as keyboards, mice, and flash drives. The rear USB 2.0 ports are for high power devices, such as iPods, USB external hard disks, etc.


THR

Originally posted by Benevolent Heretic
Anything made to work in a USB2 will also work in a USB1, but not vice versa.

[edit on 19-3-2007 by Benevolent Heretic]

Actually, devices that require USB 2.0 cannot use a USB 1.1 port, as the USB 1.1 does not output enough power to charge or run the device.

I know this because my iMac had 2 USB 1.1 ports on the keyboard, and I tried connecting my iPod to it, and it said that I needed to connect to a USB 2.0 port, because USB 1.1 does not output enough power to run this device.

Devices that require USB 1.1 can run using a USB 2.0 port. Not the other way around, though.


THR

Originally posted by jsobecky
The install instructions actually say that plugging the drive into a front USB port will cause it to malfunction, which covers a wide array of problems, including speed-related ones.

That's because it's an industry standard to have low power USB in the front.
The manual was assuming your front ports were 1.1, and, just in case, they said that so they would be liable in the event of damage to the product or your computer.


THR

TheRanchMan

Your explanation sounds like the most logical so far. To recap what you said, in my own words:

Rear ports are 2.0, which supply more power than front ports, which are 1.1. This is true for "older" PC's, which had a mixture of the two types. "Newer" PC's USB ports are all 2.0.

The disk manufacturer has no idea which type of PC you have, so they play it safe by specifying rear ports.

Thanks.

[edit on 22-3-2007 by jsobecky]

Pretty much, yes.


THR

While all modern PCs use USB 2.0 for rear and front pannel usb ports keep in mind that the rear ports are directly on the mother board and the front pannel ports are connected via a cable to a hub, usually seperately located from the usb controller on the board. So on a store bought pc the fron pannel ports are always slower.

According to the USB specifications, both USB 1.1 and USB 2 are rated to supply the same amount of power per port (500mA max).

The issue with power and front/back USB ports is that a rear port socket is fed 5V straight from the motherboard, usually close to where the 5V is supplied to the board via your ATX power connector, therefore the best chance of a good, solid 5V supply.

Your front ports are usually fed via a longer conductive trace on the board, and then via a wiring harness to the front sockets. This, combined with the sometimes marginally wired USB connector cable from the socket to the device can cause enough of a voltage drop to cause devices which are already at the limits of the USB power specification (such as USB powered HDDs) to operate unreliably or not at all.

Republicans plug into the front.

Democrats plug into the rear.

Originally posted by jsobecky
Hardware geeks: What is the difference between the USB ports in the front of a PC and the ones in the back of the PC?

The reason I ask is b/c the install intructions that came with an external Seagate HD specifically stated to plug the USB cable into a rear USB port, or else damage to the HD could occur.

doesnt matter, plugging into the back would boost cosmetic appearance because you dont want abunch of cables out of the front of the machine.

The RanchMan has the best answer. The front ports supplied less power in older machines, of course this may be different with newer PCs? Some things won't run off the front ports. Laptops were the same way to my understanding.

Troy

I have been building computers for a long time (way before USB) and have never noticed a motherboard that had two versions of USB. And no offense to RanchMan but that is the first I have heard of Specifying placement of ports due to power requirements. USB 1 and 2 have the same power output. A USB 2 cable can have the length of 5 meters so voltage drip on the short leads from the MB to the front of the case is not going to be noticeable.
I would guess that telling you to avoid the front ports keeps things from accidentally being unplugged.

my 2 cents