USB A
The number of USB inputs located on the body of the card reader or hub (see “Type”). This parameter determines the number of USB ports you will have at your disposal after connecting the device. "Pure" card readers and combined models usually have 1,
2, and even
3 USB inputs, while hubs typically feature
4 or more ports.
USB C
Number of USB Type C ports for connecting peripheral devices provided in the hub design (or a card reader with hub functionality — see "Type").
The port itself is small — only slightly larger than microUSB — with a reversible design that allows the plug to be inserted in either direction. This is why it has gained respect and is actively replacing the classic USB port.
Despite its small size, USB Type C is used in both portable devices and desktop PCs and their peripherals. However, few such devices have been released so far; as a result, hubs typically include
1 USB C port or
2 type C inputs.
The USB connector interface (version) primarily determines speed.
— 2.0. The outdated 2.0 version provides data transfer speeds up to 480 Mbps. Found only in USB A ports.
— 3.2 gen1. Previously named standards 3.1 gen1 and 3.0. This version ensures a tenfold increase in maximum speed (4.8 Gbps) and higher power capacity, allowing for the connection of energy-intensive devices and extensive splitters.
— 3.2 gen2. A further improvement of the 3.2 gen1 standard (and typically, with several renamings from the previous 3.1 gen1 and simply 3.1), achieving a maximum speed of 10 Gbps and even higher power capacity for external devices.
However, the final speed depends not so much on the input port as on the USB version of the hub (card reader) connection to the PC.
HDMI
HDMI is the most popular of modern multimedia digital interfaces. It is specifically designed for HD content and provides the transmission of high-resolution video and multi-channel audio through a single cable.
HDMI outputs are mainly found in hubs connected via USB Type C and compatible with the Thunderbolt interface (see "Connection"). Essentially, to use HDMI, you will need to connect the device to a Thunderbolt v3 port — a "pure" USB Type C does not support video transmission. This capability may be useful if an external screen is intended for HDMI connection, but your PC or laptop lacks such ports, or they are occupied or unavailable for other reasons. HDMI can have different versions, which affects its bandwidth. For instance, to transmit 4K video at 60 fps, you need
HDMI v 2.0 or 2.1. And
multiple ports will allow you to connect more than one monitor.
