USB, SATA and serial port cards are expansion cards that add extra USB ports, SATA connections or RS-232 serial ports to a desktop PC, workstation or server. Our range of over 200 models covers all three types, with cards from DELOCK, EXSYS, INLINE and StarTech among the leading brands.
How to choose a USB, SATA or serial port card
Slot type and bracket. Most current cards use PCI Express, in x1, x4 or x8 lengths, and a short card works in any longer slot. Check which slot is free on your motherboard and whether your case needs a low-profile bracket. Older PCI cards also exist for legacy machines.
Port type and speed. For USB, look at the standard: USB 3.2 Gen 1 runs at 5 Gbit/s and Gen 2 at 10 Gbit/s, and you should decide between USB-A and USB-C sockets. For SATA, SATA III at 6 Gbit/s is the usual choice for SSDs and hard drives. Serial cards are mostly RS-232, while RS-422 and RS-485 are used in industrial setups.
Number of ports and controller. Serial cards are sold with one, two, four or more ports, so count the devices you need to connect and leave room to grow. On multi-port USB cards, check whether each port has its own controller channel, because shared channels split the bandwidth between connected devices.
Power connection. USB cards that drive several external drives or other power-hungry devices often need an extra power connector, usually SATA or Molex, taken from the power supply. Make sure your power supply has a spare lead.
Operating system support. Check that the manufacturer lists drivers for your system, such as Windows 11 or a current Linux distribution. This matters most for serial cards in industrial or lab equipment, where software can be tied to specific COM port behaviour.
Brands we carry
- DELOCK: a German brand known for interface cards, cables and adapters, which makes it easy to find a matching card and cabling from one source.
- EXSYS: a German manufacturer specialising in serial, USB and other I/O expansion cards, including multi-port serial models.
- INLINE: a German brand covering cables, adapters and PC accessories, with straightforward add-on cards for common upgrades.
- StarTech: a Canadian company focused on connectivity products, widely used by IT departments for USB, SATA and serial expansion.
- Broadcom: a major name in storage controllers, whose SATA and SAS host bus adapters are common in servers and workstations.
- Sonnet: known for expansion and storage products for Mac and professional workstations, including Thunderbolt solutions.
Also in our range: VALUE, RENKFORCE, ROLINE, DIGITUS, INTER-TECH and CONCEPTRONIC.
Frequently asked questions
Do I need a USB card if my motherboard already has USB ports?
You only need one if you have run out of ports or want a newer standard than your board offers. A card can add USB-C or faster USB 3.2 ports to an older PC. It can also give you more ports on a dedicated controller, which helps when you connect several high-speed devices at once.
Can I add more SATA ports with a PCIe card?
Yes, a PCIe SATA card adds extra ports for internal drives when your motherboard has run out of connectors. Check the number of ports and the SATA speed, and make sure the card works with your operating system. For servers and RAID setups, a dedicated controller or host bus adapter is usually the better fit.
What is a serial port card used for?
A serial port card adds RS-232 COM ports for equipment that still communicates over serial. Typical examples are industrial machines, test and measurement devices, card readers, point-of-sale hardware and network equipment consoles. Multi-port versions let you connect several such devices to one PC.
Will a PCIe x1 card work in an x16 slot?
Yes, a PCIe x1 card works in a longer slot such as x4 or x16, because PCI Express is physically and electrically backward compatible in that direction. The card will still run at x1 speed. Just make sure the slot is free and that the card's bracket fits your case.
