JustCurious
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Speed of both USB ports

Sun Sep 21, 2014 3:05 pm

The Pi has two USB ports. They are 2.0 HS ports. My Question is: does the 480Mbs bandwidth apply for both ports together, or for each port individually?

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pluggy
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Re: Speed of both USB ports

Sun Sep 21, 2014 3:15 pm

Its one port split into 2 (or 4 on a B+) so its a total. I wouldn't expect anywhere close to the theoretical 480 Mb/s either.......
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Joe Schmoe
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Re: Speed of both USB ports

Sun Sep 21, 2014 3:47 pm

If you use the ethernet, that counts as well.

In fact, the 9512 is a 3 port hub and the 9514 is a 5 port hub.

Aside: In an x86 laptop or desktop, does each USB port that is exposed on the case get its own 480 Mb/s allotment, or are they allowed to be chained together (like they are on the Pi) as well?
And some folks need to stop being fanboys and see the forest behind the trees.

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W. H. Heydt
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Re: Speed of both USB ports

Mon Sep 22, 2014 1:49 am

Joe Schmoe wrote: Aside: In an x86 laptop or desktop, does each USB port that is exposed on the case get its own 480 Mb/s allotment, or are they allowed to be chained together (like they are on the Pi) as well?
First step would be to cehck how they're wired to the motherboard. Do they use one hearder row or two? (It's usually two.) From there, you'd have to check the m/b schematics to see how the header is connected to the southbridge, and then check the specs on the southbridge.

At leat on the Pi we know where the real root of the USB network is and what it is capable of...even if the best description of that is "not much".

Joe Schmoe
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Joined: Sun Jan 15, 2012 1:11 pm

Re: Speed of both USB ports

Mon Sep 22, 2014 1:59 am

At leat on the Pi we know where the real root of the USB network is and what it is capable of...even if the best description of that is "not much".
Heh heh…
And some folks need to stop being fanboys and see the forest behind the trees.

(One of the best lines I've seen on this board lately)

jamesh
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Re: Speed of both USB ports

Mon Sep 22, 2014 7:30 am

W. H. Heydt wrote:
Joe Schmoe wrote: Aside: In an x86 laptop or desktop, does each USB port that is exposed on the case get its own 480 Mb/s allotment, or are they allowed to be chained together (like they are on the Pi) as well?
First step would be to cehck how they're wired to the motherboard. Do they use one hearder row or two? (It's usually two.) From there, you'd have to check the m/b schematics to see how the header is connected to the southbridge, and then check the specs on the southbridge.

At leat on the Pi we know where the real root of the USB network is and what it is capable of...even if the best description of that is "not much".
I raise your "not much " with a "usually enough"
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