# ExpressCard
**ExpressCard** is a laptop expansion-card standard unveiled by PCMCIA in September 2003 as the successor to [PC Card](https://www.edgepedia.org/pc-card) and CardBus, carrying [PCI Express](https://www.edgepedia.org/pci-express) and USB 2.0 signals over a single hot-pluggable 26-pin slot.[1](https://www.patents-review.com/a/20050138288-dual-mode-usb-pci-express-device.html) • [2](https://usb.org/expresscard) The standard was developed by PCMCIA with assistance from the USB Implementers Forum (USB-IF) and PCI-SIG, with contributors including Hewlett Packard, IBM, Intel, Lexar Media, Microsoft, SCM Microsystems, and [Texas Instruments](https://www.edgepedia.org/texas-instruments).[3](https://pcisig.com/faq/pciexpress?page=1) After PCMCIA's dissolution, stewardship of ExpressCard passed to the USB-IF.[2](https://usb.org/expresscard)
| Key fact | Detail |
|---|---|
| Formats | ExpressCard/34 (34 × 75 mm) and ExpressCard/54 (54 × 75 mm), both 5 mm thick; 75 mm length is 10.6 mm shorter than a standard PC Card[4](https://ptacts.uspto.gov/ptacts/public-informations/petitions/1546468/download-documents?artifactId=7bAtvZ_roWo5owqy_GX7-WItyv8-diCA0-S7QxLfWSA9ewcrXu9BFyI) |
| Connector | 26-pin host and module connector, shared by both card widths[5](https://static.datasheets.com/doc/15406066-te-connectivity-1759044-1-ds.pdf) |
| ExpressCard 1.0 electricals | One PCI Express x1 lane at 2.5 Gbps in each direction (Base Specification 1.0a) plus low-, full-, and high-speed USB 2.0 (480 Mbps)[2](https://usb.org/expresscard) • [6](https://d1.amobbs.com/bbs_upload782111/files_30/ourdev_565505L0VLQR.pdf) |
| ExpressCard 2.0 (March 2009) | Adopts PCI Express 2.0 and SuperSpeed USB 3.0, roughly 10x faster on paper, backward compatible with 1.0[7](https://arstechnica.com/gadgets/2009/03/expresscard-hits-the-fast-lane-debuts-20-standard/) • [8](https://www.slashgear.com/expresscard-20-finalized-5gbps-for-10x-faster-cards-0946480/) |
| Thermal guidance | Recommended maximum TDP under 1.3 W for /34 modules and under 2.1 W for /54 modules[6](https://d1.amobbs.com/bbs_upload782111/files_30/ourdev_565505L0VLQR.pdf) |
| Hot-plug | Install and remove modules at any time without switching off the system; slot power controlled by a wired module-presence detection scheme[2](https://usb.org/expresscard) |
| Typical devices | TV tuners, Bluetooth adapters, flash-card readers, 3G data cards, serial ports, SmartCard and CompactFlash readers, 1.8-inch drives[9](https://www.macworld.com/article/174839/expresscard-2.html) • [2](https://usb.org/expresscard) |
## Physical formats and connector
The standard defines two module formats: ExpressCard/34, 34 mm wide, and ExpressCard/54, 54 mm wide, both 75 mm long and 5 mm thick, the same thickness as a Type II PC Card.[4](https://ptacts.uspto.gov/ptacts/public-informations/petitions/1546468/download-documents?artifactId=7bAtvZ_roWo5owqy_GX7-WItyv8-diCA0-S7QxLfWSA9ewcrXu9BFyI) Both use the same 26-pin connector interface, and the specification supports a universal slot configuration that accepts either module; hosts may instead implement 34-only slots.[4](https://ptacts.uspto.gov/ptacts/public-informations/petitions/1546468/download-documents?artifactId=7bAtvZ_roWo5owqy_GX7-WItyv8-diCA0-S7QxLfWSA9ewcrXu9BFyI) • [6](https://d1.amobbs.com/bbs_upload782111/files_30/ourdev_565505L0VLQR.pdf)
The wider format exists for components that do not fit the narrower card. PCMCIA's specification notes that the ExpressCard/54 module affords an application nominally 140% the internal volume and 160% the thermal dissipation capacity of the ExpressCard/34 module, and recommends maximum thermal design power of less than 1.3 W for /34 modules and less than 2.1 W for /54 modules.[6](https://d1.amobbs.com/bbs_upload782111/files_30/ourdev_565505L0VLQR.pdf) The USB-IF lists SmartCard readers, [CompactFlash](https://www.edgepedia.org/compactflash) readers, and 1.8-inch disk drives as the kinds of components accommodated by the /54 format.[2](https://usb.org/expresscard)
Slots may optionally provide a two-wire SMBus sideband for features such as remote alerting and sideband radio control, plus a wake signal that is supported only by ExpressCard PCI Express functions; USB functions do not use the wake protocol.[6](https://d1.amobbs.com/bbs_upload782111/files_30/ourdev_565505L0VLQR.pdf)
## Electrical interface and versions
ExpressCard replaced the parallel CardBus architecture with two serial interfaces. Each compliant host slot must support a single PCI Express lane (x1) at the baseline 2.5 Gbps data rate in each direction, as defined in the PCI Express Base Specification 1.0a, together with the low-, full-, and high-speed USB 2.0 data rates; supporting both interfaces is a condition of compliance.[2](https://usb.org/expresscard) • [6](https://d1.amobbs.com/bbs_upload782111/files_30/ourdev_565505L0VLQR.pdf) USB 2.0 is a 480 Mbps differential serial bus standardized by the USB-IF, and PCI Express is a dual-simplex 2.5 Gbps differential serial link standardized by PCI-SIG.[6](https://d1.amobbs.com/bbs_upload782111/files_30/ourdev_565505L0VLQR.pdf)
**ExpressCard 2.0.** In March 2009 PCMCIA unveiled ExpressCard 2.0, which takes advantage of PCI Express 2.0 and the finalized [USB 3.0](https://www.edgepedia.org/usb-3-0) standard, offering roughly 10x faster speeds on paper, with backward and forward compatibility between 1.0 and 2.0 slots and devices.[7](https://arstechnica.com/gadgets/2009/03/expresscard-hits-the-fast-lane-debuts-20-standard/) Trade press reported transfer speeds boosted up to 10 times compared with ExpressCard 1.2 and support for SuperSpeed USB 3.0, with up to 5 Gbps bandwidth envisaged for eSATA ports, high-speed storage such as SSDs, and streaming video and audio adapters.[8](https://www.slashgear.com/expresscard-20-finalized-5gbps-for-10x-faster-cards-0946480/) The two reports differ on when first products would arrive: [Ars Technica](https://www.edgepedia.org/ars-technica) reported PCMCIA expected ExpressCard 2.0 devices in 2010,[7](https://arstechnica.com/gadgets/2009/03/expresscard-hits-the-fast-lane-debuts-20-standard/) while SlashGear reported first products expected in 2011.[8](https://www.slashgear.com/expresscard-20-finalized-5gbps-for-10x-faster-cards-0946480/)
## Typical devices and uses
ExpressCard was designed as the successor to the PC Card standard, using PCI Express and USB 2.0 to improve bandwidth for peripherals such as TV tuners, [Bluetooth](https://www.edgepedia.org/bluetooth) adapters, and flash memory cards.[9](https://www.macworld.com/article/174839/expresscard-2.html) PCMCIA showed some of the first ExpressCard products, including notebooks from Fujitsu-Siemens, IBM, and Toshiba, at the CeBIT trade show in Hannover, Germany.[9](https://www.macworld.com/article/174839/expresscard-2.html)
The card catalog that followed spanned both interfaces. On the USB side, examples include the Papouch SSPX-100, a fully ExpressCard 1.0-compliant USB-based ExpressCard/34 module providing a 16550 UART with one DB-9 RS-232 port at baud rates up to 115.2 Kbps, the kind of serial module used to connect legacy industrial equipment.[10](https://cdn.papouch.com/data/user-content/old_eshop/files/ExpressCard_RS485_1/express-card.pdf) On the storage and communications side, 3G data cards were common enough that SlashGear cited them as the example of existing accessories that would keep working in 2.0 sockets.[8](https://www.slashgear.com/expresscard-20-finalized-5gbps-for-10x-faster-cards-0946480/) For 2.0, PCMCIA expected eSATA drives, video streaming, and external high-performance SSDs to drive the device category.[7](https://arstechnica.com/gadgets/2009/03/expresscard-hits-the-fast-lane-debuts-20-standard/)
## How it compares with PC Card, Mini PCIe, and Thunderbolt
Against its predecessor, ExpressCard's advantage was architectural simplification. The technology uses a simpler connector and eliminates the CardBus slot controller by connecting modules directly to PCI Express and USB ports in the host, lowering the cost of slot implementations.[2](https://usb.org/expresscard) PCMCIA also promoted the 26-pin count as making the slot simpler for PC manufacturers to adopt.[11](https://www.zdnet.com/article/in-pc-design-harbingers-of-shrink/) The formats are not physically compatible in the other direction: older 54 mm-wide PC Cards do not fit ExpressCard slots, and the IBM ThinkPad T43 and Toshiba Tecra S2 shipped with both slot types side by side during the transition.[9](https://www.macworld.com/article/174839/expresscard-2.html)
The eGPU community framed ExpressCard 2.0 explicitly as a lower-cost, lower-bandwidth eGPU interface alternative to [Thunderbolt](https://www.edgepedia.org/thunderbolt) in older notebooks.[12](https://egpu.io/expresscard-2-0-egpu-interface-pros-cons-candidate-notebook-list/)
## Decline, eGPU afterlife, and legacy
ExpressCard slots appeared mainly in a cohort of 2011 to 2013 durable business-grade notebooks, which the cited community source described as available cheaply second-hand; on 2nd through 5th generation [Intel Core](https://www.edgepedia.org/intel-core) hosts an ExpressCard 2.0 slot provides 4 Gbps of PCIe x1 2.0 bandwidth, and 2 Gbps on 1st generation or older.[12](https://egpu.io/expresscard-2-0-egpu-interface-pros-cons-candidate-notebook-list/) Four 7th/6th generation Lenovo workstations carried a rare ExpressCard 3.0 (8Gbps-EC3) port alongside Thunderbolt 3.[12](https://egpu.io/expresscard-2-0-egpu-interface-pros-cons-candidate-notebook-list/)
**The eGPU afterlife.** The slot's most durable practical use has been attaching desktop graphics cards to old laptops. Examples cited by the eGPU community include a PCE164P-N03 with a DIY ExpressCard adapter, the EXP GDC Beast 8.4d, and the BPlus PE4C-EC060A 3.0; the interface is hot-pluggable, which is required for NVIDIA GTX 10xx cards, and setups often work plug-and-play or need only minor tweaking of Windows error 12 (resource allocation).[12](https://egpu.io/expresscard-2-0-egpu-interface-pros-cons-candidate-notebook-list/) [Performance](https://www.edgepedia.org/performance) is constrained by the single lane: the community's reference point is that 16 Gbps (x4 2.0) bandwidth is needed to reach about 85% of desktop-level eGPU performance, so the 4 Gbps ExpressCard link delivers compromised results, and attaching an external monitor directly to the eGPU is required to maximize performance on the narrow link.[12](https://egpu.io/expresscard-2-0-egpu-interface-pros-cons-candidate-notebook-list/)
## References
1. [Dual mode USB and PCI express device, Patent Application (patents-review.com)](https://www.patents-review.com/a/20050138288-dual-mode-usb-pci-express-device.html)
2. [ExpressCard, USB Implementers Forum](https://usb.org/expresscard)
3. [PCI-SIG FAQ on PCI Express](https://pcisig.com/faq/pciexpress?page=1)
4. [About ExpressCard Technology, USPTO PTACTS petition document](https://ptacts.uspto.gov/ptacts/public-informations/petitions/1546468/download-documents?artifactId=7bAtvZ_roWo5owqy_GX7-WItyv8-diCA0-S7QxLfWSA9ewcrXu9BFyI)
5. [TE Connectivity ExpressCard connector datasheet 1759044-1](https://static.datasheets.com/doc/15406066-te-connectivity-1759044-1-ds.pdf)
6. [ExpressCard Standard, PCMCIA/JEITA specification (archived PDF)](https://d1.amobbs.com/bbs_upload782111/files_30/ourdev_565505L0VLQR.pdf)
7. [ExpressCard hits the fast lane; debuts 2.0 standard, Ars Technica (March 2009)](https://arstechnica.com/gadgets/2009/03/expresscard-hits-the-fast-lane-debuts-20-standard/)
8. [ExpressCard 2.0 Finalized: 5Gbps For 10x Faster Cards, SlashGear](https://www.slashgear.com/expresscard-20-finalized-5gbps-for-10x-faster-cards-0946480/)
9. [Faster ExpressCards on tap for laptops, Macworld/IDG](https://www.macworld.com/article/174839/expresscard-2.html)
10. [SSPX-100 ExpressCard RS-232 serial module datasheet, Papouch](https://cdn.papouch.com/data/user-content/old_eshop/files/ExpressCard_RS485_1/express-card.pdf)
11. [In PC design, harbingers of shrink, ZDNet](https://www.zdnet.com/article/in-pc-design-harbingers-of-shrink/)
12. [Expresscard 2.0 eGPUs, pros, cons and candidate notebooks, eGPU.io](https://egpu.io/expresscard-2-0-egpu-interface-pros-cons-candidate-notebook-list/)
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*Topic: Encyclopedia › Technology and the built world › Computing and digital systems › Computer hardware › Boards, peripherals & form factors › Peripherals & expansion hardware › Expansion cards and add-in boards*
*Initially written Sep 17, 2026 · Reviewed: Oct 15, 2026 · Edited: Oct 15, 2026 · Last review: Oct 15, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license