Serial port cards are essential for connecting legacy devices or specialized equipment to modern computers. Ensuring compatibility and reliable performance is key, especially in industrial, scientific, or networking environments where these connections are critical. Choosing the right card can prevent connectivity issues and ensure seamless operation of your peripherals.
Looking for the best Serial Port Cards?
Discover now our comparison of the best Serial Port Cards. It is never easy to choose from the wide range of offers. On the market, you will find an incalculable number of models, all at different prices. And as you will discover, the best Serial Port Cards are not always the ones at the highest prices! Many criteria are used, and they make the richness and relevance of this comparison.
To help you make the best choice among the hundreds of products available, we have decided to offer you a comparison of the Serial Port Cards in order to find the best quality/price ratio. In this ranking, you will find products listed according to their price, but also their characteristics and the opinions of other customers. Also discover our comparisons by categories. You won’t have to choose your products at random anymore.
- Dual Serial Ports: Provides two independent RS232 serial ports, enabling connections with multiple serial DB9 port (RS232 communication) devices, significantly expanding your system's connectivity.
- Wide Compatibility: Requires driver installation for Windows XP, Vista, 7, 8.x, 10, 11 (32/64-bit) systems. For Linux kernels 2.6.x, 3.x, 4.x, 5.x, source code on the driver CD can be compiled.
- Advanced Chip Solution: Utilizes the ASIX AX99100 solution supporting 256-byte depth FIFO transfer on-chip, suitable for Intel, AMD, and ARM hardware platforms.
- Versatile Bracket Design: Comes with a full-size bracket for standard PCs and a low-profile bracket for 2U computers. Compatible with PCIe x1 slots and also fits x4, x8, x16 slots.
- Important Notes:Ensure your computer has an available PCIe slot,for 2U computers, manually replace with the low-profile bracket,for desktop computers, install the correct driver from the Mini-CD.
- 1. PCIE-SE2 allow users add 2X RS232 BD9 serial Ports on desktop PCs or industrial devices by motherboard PCI Express slot.
- 2. Seamless connect to serial DB9 ports device such as POS system, industrial testing and control device, security system, logistic management equipment, scanners and printers.
- 3. Need to install driver on Windows XP, Vista, 7, 8.x, 10, 11 (32/64bit) systems. Linux kernel 2.6.x, 3.x, 4.x, 5.x need to refer compile source code from the driver CD.
- 4. Selected by ASIX AX99100 solution supports on chip 256-byte depth FIFO in transmit. Works on Intel, AMD, ARM hardware platform.
- 5. The full-size bracket on this expansion card will works on standard size PCs. The 2X low profile bracket for slim PCs. Based on PCIE X1 interface, will works on X1, X4, X8, X16 slot.
- 6. ATTENTION: 1. Must make sure users PCs have empty PCIE slot.2. Slim PC users need change to low profile bracket by hand. 3.Please install correct driver from Mini-CD for desktop PCs.
- Fully compliant with PCI-E base Specification, Revision 1.0A
- Support for D1, D2, D3hot and D3cold
- Utilizes 100-MHz Differential PCI-E common reference Clock
- 2 16C450/550/extended 550 compatible UART
- Bi-directional speeds from 50bps to 16Mbps/port
- Fully Compliant with PCI-e Base Specification, Revision 1.0a
- Support for D1, D2, D3hot and D3cold
- Utilizes 100-Mhz Differential PCI-e Common Reference Clock
- Custom BAUD Rates Supported with External Clock or by Programming Internal PLL
- 5, 6, 7, 8 and 9-bit Serial Format Support
- Support MODEM Signals CTS, DSR, RI, DCD, the DTR, RTS, Convert RS232 Level
- 1 PORT SERIAL CARD: Serial controller card w/ 16950 UART based on ASIX AX99100, allows 1x DB9 port w/bi-directional RS232 speeds up to 921.6Kbps per port, available 256 byte FIFO buffer & 9th data bit; Upgraded version of our popular card PEX1S952LP
- OPTIONAL CONFIGURABLE POWER: PCI Express RS232 serial adapter card provides choice of 12v, 5v, or none through pin 9 w/up to 2A total
- STANDARD PROFILE & LOW PROFILE BRACKET: PCIe serial card comes w/ a low profile bracket pre-installed & 1x full profile bracket is incl for versatile install; Supports Windows & Linux
- VERSATILE APPLICATIONS: For low/standard profile desktop/servers w/ uses in point of sale terminals, PLCs, control/automation in factories, scientific sensors, medical equipment, scanner, oscilloscope
- 2 PORT SERIAL CARD: Serial controller card w/16950 UART based on ASIX AX99100, allows 2x DB9 ports w/bi-directional RS232 speeds up to 921.6Kbps per port, available 256 byte FIFO buffer & 9th data bit; Upgraded version of our popular card PEX2S952LP
- OPTIONAL CONFIGURABLE POWER: PCI Express RS232 serial adapter card provides choice of 12v, 5v, or none through pin 9 w/up to 2A total; Each of the 2 ports are individually configurable
- STANDARD PROFILE & LOW PROFILE BRACKET: PCIe multiport serial card comes w/ low profile bracket preinstalled & a full profile bracket is incl for versatile install; supports Windows XP and up & Linux
- VERSATILE APPLICATIONS: For standard/low profile desktop/servers w/ uses in point of sale terminals, PLCs, control/automation in factories, scientific sensors, medical equipment, scanner, oscilloscope
- Expansion Interface: Easily add 2 RS232 DB9 serial ports to desktop PCs or industrial devices via the motherboard's PCI Express slot, meeting a variety of device connection needs
- Wide Compatibility: Seamlessly connect to DB9 serial devices such as POS systems, industrial testing and control equipment, security systems, logistics management devices, scanners, and printers, suitable for various application scenarios
- Multi-Platform Support: Driver compatible with Windows XP, Vista, 7, 8.x, 10, 11 (32/64-bit) and Linux kernels 2.6.x, 3.x, 4.x, 5.x, ensuring smooth installation and use across different systems
- Efficient Data Transmission: Utilizes the ASIX AX99100 solution, supporting 256-byte deep FIFO transmission, compatible with Intel, AMD, and ARM hardware platforms, providing stable serial data transmission performance
- Flexible Installation: Comes with a standard full-size bracket for standard PCs, and includes 2 low-profile brackets for perfect compatibility with slim PCs. Based on the PCIe X1 interface, compatible with X1, X4, X8, and X16 slots
- Important: Ensure your PC has an available PCIe slot, switch to the low-profile bracket for slim PCs, and install the correct driver from the Mini-CD for desktop use
- Plug and Play, automatically assigned IRQ and I / O address.
- You can manually change the port number of additional serial port card.
- Support PCI I / Q shared.
- Consistent with PCI Rev2.1 Agreement.
- Consistent with standard input and output of 16C550 UART with 16 byte transmit-receive FIFO.
- PCI CARD WITH SERIAL & PARALLEL PORTS: Using one PCI bus, add a DB25 parallel & two DB9 RS232 ports to your computer; Serial Parallel PCI Card installs in 2x full profile or 3x low profile expansion slots; Auto IRQ & IO assignment; Supports IRQ Sharing
- TECH SPECS: Parallel Speeds up to 1.5Mbps | Supports SPP/Byte/ECP/EPP modes | Compatible with IEEE 1284 | Asix MCS9865 chip | RS-232 speeds up to 115.2 Kbps | 16C550 UART | 256 byte FIFO buffer | 5-9 bit character | Even, Odd, No, Space or Mark Parity
- VERSATILE APPLICATIONS: PCI expansion combo card adds LPT Printer & two COM serial ports working with printers, scanners, plotters, point of sale terminals, PLCs, control/automation in factories, scientific sensors, medical equipment, oscilloscope
- STANDARD PROFILE & LOW PROFILE BRACKETs: PCI multiport Parallel LPT & dual serial COM adapter card installs using 2x standard bracket (pre-installed) or 3x low profile brackets (incl); Supports Windows 7 and up, Linux 2.6.x to 5.x
- This card capability allow for upgrade with additional serial cards to your computer easily. Note: Open the "CH38XDRV"file in the CD to install.
- 2 x 16C550 Fast Uart serial ports, supporting data transfer rates up to 230400Bps.
- Plug and Play, Automatically selects IRQ & IO address, Supports IRQ sharing.
- Compliant with ExpressCard/34mm Standard; Compatible to 1-Lane (x1) PCI-Express Throughput.
- Operating System: Windows 32bit 2000/XP/2003 Server/Vista and 64bit XP/2003 Server/Vista/WIN7/WIN8/WIN10/WIN11/Linux. (If there was any problem with PCIE 2 port serial expansion card, pls feel free to contact us, we will provide a solution within 24hrs.)
- MCS9922 Chipset
- Compatible with Industrial Standard 16C550 UART. On Chip 256-byte Depth FIFO in Transmit.
- Transfer data rates up to 250Kbps on each port. Supports hardware and software flow control. Supports 5, 6, 7, 8-bit Serial format
- Fully compliant with PCI-Express base Specification Revision 1. 0a
- Single-lane (x1) PCI-Express with throughput up to 2. 5Gbps
- Form Factor: Low profile
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Last update on 2026-04-16 / Affiliate links / Images from Amazon Product Advertising API
How to Choose the Best Serial Port Cards
Understanding Serial Port Types
Serial port cards primarily offer RS-232 interfaces, but variations exist. RS-422 and RS-485 offer longer distances and multi-drop capabilities, often used in industrial automation and networking. Consider the specific protocol your devices require. Most cards utilize PCI, PCIe, or USB interfaces to connect to your computer. PCIe is the modern standard for internal cards, offering higher bandwidth than older PCI slots.
Key Features to Consider
- Number of Ports: Determine how many serial devices you need to connect simultaneously. Cards are available with one, two, four, or even more ports.
- Connector Type: Most common is DB9 (9-pin male or female), but some devices may use DB25 or other connectors. Ensure the card's connector matches your devices.
- Chipset: The chipset (e.g., FTDI, ASIX, CH340) influences driver support, stability, and performance. Look for well-regarded chipsets known for reliability.
- Power Requirements: Some serial devices require power from the serial port itself (often referred to as "phantom power"). Check if the card offers selectable or adjustable power output if needed.
- Operating System Compatibility: Ensure the card has drivers available for your specific operating system, whether it's Windows, macOS, or Linux.
Installation and Driver Considerations
Internal cards (PCIe) require opening your computer case. External USB-to-serial adapters are plug-and-play for most modern systems. Always download the latest drivers from the manufacturer's website to ensure optimal performance and compatibility. Check reviews for common driver issues or installation hurdles.
Use Case Scenarios
These cards are vital for connecting point-of-sale systems, industrial machinery, scientific instruments, GPS receivers, and older networking equipment. For robust, long-distance communication or connecting multiple devices on a single bus, consider RS-485 or RS-422 options. For general-purpose device connections, RS-232 is usually sufficient.
