USB3 Hub / USB 2 equipment !

[Skywatcher 200]

Hi all, Just after a bit of info,

I have a USB3 Port on my laptop and a USB3 Hub,  would i be able to connect my USB2 equipment via this hub ?

Thanks

Andy

[ajk]

Yes

[RuralBill]

Hi,

yes no problem, the USB 3.0 is backwardly compatible with USB 2.0, even though the USB 3.0 female socket  on the hub, is bigger, you can still put a USB 2.0 male plug into them too, if required, although in your example you don't need to as you are using a USB 3.0 hub.

hope that helps

Bill

[Skywatcher 200]

thanks for that ajk,

Had to look twice at your tag as ajk are my initials,

[Skywatcher 200]

Thanks RuralBill,

[ajk]

4 minutes ago, Skywatcher 200 said:

Had to look twice at your tag as ajk are my initials

Oddly enough, mine too

Some extra info. USB is backwards compatible (USB3 can use 3, 2 and 1, USB2 can use 2 and 1 and USB1 can use, err, 1).

In fact, if you have a USB3 on your computer/laptop you should always try and use a USB3 hub for USB2 peripherals/equipment if you possibly can (and if you own a USB2 hub and have a USB3 on your computer I would always recommend your next upgrade should be to replace the USB2 hub with a USB3 one).

Just don't always buy the cheapest USB3 hub and make sure it's a self powered one (yeah, even for USB3 which is supposed to be better at re-powering downstream devices). Always read the reviews before trying to save a few £ on USB hubs.

 

[psamathe]

I did read that if you connect any USB2 device onto a USB3 hub then it will pull the entire hub (all connected devices) down to USB 2 (i.e. even any USB 3 devices will be "pulled-down" to USB 2).  But just something I read, repeating the words of others and not claiming expertise in USB releases.

But, when I purchased my USB 3 hub, getting USB 3 did not seem any more expensive than the USB 2 ones so I thought can't lose getting USB 3.

Ian

[ajk]

14 minutes ago, psamathe said:

(i.e. even any USB 3 devices will be "pulled-down" to USB 2)

This is incorrect. Each port negotiates it's speed with it's upstream pipe to get the best possible speed for the downstream peripheral.

However, remember, the upstream bandwidth is fixed at USB3 speed. So two downstream USB3 peripherals cannot get full upstream speed, they are sharing a single upstream connection.

So, just like with Ethernet networks, you try your best to keep the upstream higher than your downstream.

So, the best configuration is use USB2 peripherals with a USB3 hub if you can. If you have a USB3 peripheral try to avoid using the USB3 hub and connect directly to your computer if you have multiple USB3 ports available.

If you must connect a USB3 peripheral to a USB3 hub along with several USB2 peripherals then you cannot expect it to go at maximum speed but it won't be downgraded to USB2 speed, it'll just slow down enough to "fit everything into the upstream speed".

 

[Skywatcher 200]

ok, i think i understand, as i only have USB2 peripherals, things should be ok.

As it stands, i have one USB2 port to a USB2 Hub that has QHY5-11 (Guide Cam) and HEQ5 Pro  connected (Guiding)

                             one USB3 port to a USB3 Hub that has QHY8L OSC  connected (Imaging)

both Hubs are powered.

Thanks for your input and help

Regards

Andy