USB А
The number of USB inputs located on the case of the card reader or hub (see "Type"). The number of USB ports that you will have at your disposal after connecting the device depends on this parameter. "Pure" card readers and combined models, usually, have 1,
2 and even
3 USB inputs, while hubs have
4 or more ports.
USB A version
This paragraph refers to the USB connector interface. The main difference between the interface versions is speed. It is worth noting that the speed of the input connector does not yet indicate the overall throughput, since the simultaneous connection of
flash drives,
phones, memory cards slows down data transfer, which anyway is limited by the interface for connecting the device itself to a PC or
laptop(item "Connection interface").
- USB 2.0. The outdated version 2.0 provides data transfer rates up to 480 Mbps. Found only in USB A ports.
- USB 3.2 gen1. The previous names of the USB 3.1 gen1 and USB 3.0 standard (they know how to confuse). This version provides 10 times the maximum speed (4.8Gbps) as well as higher power supply, which allows you to connect power-hungry devices and large splitters.
- USB 3.2 gen2. Further improvement of the USB 3.2 gen1 standard (and, as is customary, the previous name USB 3.1 gen1 and simply USB 3.1, which was renamed more than once), made it possible to achieve a maximum speed of 10 Gbps and even higher power for external devices.
HDMI
HDMI is the most popular of today's multimedia digital interfaces. It is specifically designed for HD content and delivers high-definition video and multi-channel audio over a single cable.
HDMI outputs are found mainly in hubs connected via USB Type C and compatible with the Thunderbolt interface (see "Connection"). Actually, to use HDMI, you will need to connect the device to the Thunderbolt v3 connector — "pure" USB Type C does not provide video transmission. This feature can be useful if the external screen is designed for HDMI connection, but there are no such connectors in the PC or laptop itself, they are busy or unavailable for another reason. At the same time, HDMI can be a different version, which affects the throughput. So to transfer video in 4K at 60 fps, you must have
HDMI v 2.0 or 2.1.
Switch
The presence of a switch that allows you to turn off the power supply to the USB ports. This function can be implemented either by one
common switch for all ports at once, or by personal
buttons for each port.
Power Delivery
The technology allows you to work at higher voltage, thereby increasing the transmitted power.
USB hubs with Power Dlivery can not only charge smartphones faster, but also power more power-hungry devices, such as laptops.
USB cable compartment
A special compartment on the case of the card reader or hub (see "Type"), in which the USB cable is placed during non-working hours. Such models are compact and easy to transport due to the fact that the wire, which tends to get confused and interfere, is hidden inside the device. For objective reasons, only devices with an external connection can have
a cable compartment(see "Intended use").
Cable length
The length of the cable supplied with the device. Mostly relevant for models with a non-removable cable that cannot be replaced.
