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The devices need electrical power, that's what it's about. The electrical output of USB ports is limited, you cannot connect just as many devices on machine A as on B because the hardware is slightly different.<br />
To change that, use USB hubs that have their own power supply.
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The devices need electrical power, that's what it's about. The electrical output of USB ports is limited, you cannot connect just as many devices on machine A as on B because the hardware is slightly different.
To change that, use USB hubs that have their own power supply.

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Both of my hubs have external power.
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I just purchased a new Lenovo T440s laptop (running Windows 7). &nbsp;It comes with 3 USB 3.0 ports. &nbsp;I currently have two of the ports occupied by USB 3.0 hubs, one with 5 devices, and the other with 7 devices. &nbsp;When I plugged my iPhone into one of the hubs I got a message that I had exceed my USB host controller capacity. &nbsp;How is this possible? &nbsp;What does it mean? &nbsp;What can I do about it? &nbsp;I've used the same configuration for years with my previous T420s laptop without any issue.<br />
<br />
Thanks,<br />
<br />
Phil
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I just purchased a new Lenovo T440s laptop (running Windows 7).  It comes with 3 USB 3.0 ports.  I currently have two of the ports occupied by USB 3.0 hubs, one with 5 devices, and the other with 7 devices.  When I plugged my iPhone into one of the hubs I got a message that I had exceed my USB host controller capacity.  How is this possible?  What does it mean?  What can I do about it?  I've used the same configuration for years with my previous T420s laptop without any issue.

Thanks,

Phil

USB 3.0 Capacity

Hardware includes cell phones and other digital living devices, tablets, computers, servers, peripherals and components, printers and scanners, gaming consoles, networking hardware such as routers, hubs, switches and modems, storage devices and security equipment such as firewalls and other appliances.

Hardware

Windows 7 is an operating system from Microsoft. Features include multi-touch support, a redesigned Windows Shell with a new taskbar, referred to as the Superbar, a home networking system called HomeGroup, and performance improvements.

Windows 7

A personal computer is a general-purpose computer whose size, capabilities and price make it useful for individuals, and is intended to be operated directly by an end-user with no intervening computer time-sharing models that allowed systems to be used by many people, usually at the same time. Personal computers may be connected to a local area network (LAN), either by a cable or a wireless connection, and through that to the Internet. A personal computer may be a laptop computer or a desktop computer running an operating system such as Windows, Linux or Macintosh OS.