Range/Series Overview
IMPORTANT: This Range/Series overview section describes the range of which this product belongs. Features of different versions might be mentioned and may not apply to the specific product on this page. Please view Specs for specification of product.
PCI Express to Serial Adapter 921.6Kbps Windows and Linux Compatible. This PCI Express RS232 serial adapter card lets you add four RS232 (DB9) serial ports to your computer through a PCI Express (PCIe) slot, as if they were native serial ports. The 4 port PCIe serial card enables you to interact with serial devices, such as card readers, printers, PIN pads, and modems, at speeds of up to 921.6Kbps.
Maximum Compatibility
With broad OS support, including for Windows and Linux, this multiport PCI E serial card is easy to integrate into mixed environments. The card comes pre-configured with a full-sized bracket, and includes an optional low-profile bracket, so installation is easy regardless of the case form factor. This expansion card is a direct replacement for PEX4S952.
Experience Optimal Technology
This PCIe to serial adapter supports the following features:
Industry standard 16950 UART compatible
Supports max baud rate of up-to 921.6Kbps
Provides 5/12V power output on Pin 9 when external power is connected
256-byte depth FIFO cache per transmitter and receiver
Supports 9, 8, 7, 6, 5 data bits (one per port)
Asix AX99100 chipset
Base PCI Express 1.1 compliant
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StarTech.com conducts thorough compatibility and performance testing on all our products to ensure we are meeting or exceeding industry standards and providing high-quality products to IT Professionals. Our local StarTech.com Technical Advisors have broad product expertise and work directly with our StarTech.com Engineers to provide support for our customers both pre and post-sales.
PEX4S953 is backed by a StarTech.com lifetime warranty and free lifetime technical support.
Specification Summary
Product Description
Startech 4-port PCI Express RS232 Serial Adapter Card, PCIe RS232 Serial Host Controller Card, PCIe to Serial DB9 Card, 16950 UART, Desktop Expansion Card, Windows, macOS, Linux - Full/Low-Profile Brackets (PEX4S953) - serial adapter - PCI Express x1 - RS-232 x 4
Device Type
Serial adapter
Interface (Bus) Type
PCI Express x1
PCI Specification Revision
PCIe 1.1
Dimensions (WxDxH)
6.3 cm
Data Link Protocol
RS-232
Data Transfer Rate
921.6 Kbps
System Requirements
Microsoft Windows Server 2003, Microsoft Windows Server 2008 R2, Microsoft Windows Server 2012, Microsoft Windows Server 2012 R2, Microsoft Windows 7 / 8 / 8.1 / 10, Microsoft Windows Server 2016, Linux 2.4.x - 2.6.x LTS versions only
Manufacturer Warranty
Limited lifetime warranty