# Comparison of memory cards

This short description is INTENTIONALLY "none" &#x2D; please see WP:SDNONE before you consider changing it! This table provides summary of comparison of various flash memory cards, as of 2025. Of memory cards (i.e. intended as such, to use e.g. internally), SD cards allow for largest capacity by far (with SDUC variant up to 4TB max. currently available, and the spec allocs up to 128max.), though the much bulkier CFexpress cards can also match the capacity. The relatively large (external) USB flash drives allow for more capacity, and are available with 8TB.

## Common information

    Unless otherwise indicated, all images are to scale.
| Card family | Standards organizations | Varieties | Entry date | Maximum commercially available capacity | Picture | Main features |
| CompactFlash | SanDisk | I | 1994 | 512 GB (CF5 128*2$^{50}$ bytes) | | Thinner (3.3 mm), flash only, now up to 512 GB, although standard goes up to 128 PB since CF 5.0 |
| CompactFlash | SanDisk | II | 1994 | 512 GB (CF5 128*2$^{50}$ bytes) | | Thicker (5.0 mm), older flash, but usually Microdrives, up to 128 PiB |
| CFexpress | CompactFlash Association | 1.0 | 2017 | 1 TB | | CFexpress Type B: XQD form factor (38.5 mm × 29.8 mm × 3.8 mm), PCIe 3.0 x2 (1.97 GB/s), NVMe |
| CFexpress | CompactFlash Association | 2.0 | 2019 | 4 TB | | CFexpress Type A: 20 mm × 28 mm × 2.8 mm, PCIe 3.0 x1 (1.0 GB/s), NVMe CFexpress Type C: 54 mm × 74 mm × 4.8 mm, PCIe 3.0 x4 (4.0 GB/s), NVMe |
| CFexpress | CompactFlash Association | – | – | – | – | PCIe 3.0 x8 (8.0 GB/s), NVMe |
| MultiMediaCard | Siemens AG, SanDisk | MMC | 1997 | 16 GB | | Slim and small (24 mm × 32 mm × 1.4 mm), up to 16 GB |
| MultiMediaCard | Siemens AG, SanDisk | RS-MMC/MMC Mobile | 2003/2005 | 16 GB | | Compact (24 mm × 18 mm × 1.4 mm), up to 16 GB |
| MultiMediaCard | Siemens AG, SanDisk | MMCplus | 2005 | 16 GB | | Compact (24 mm × 32 mm × 1.4 mm), swifter, optional DRM, up to 16 GB |
| MultiMediaCard | Siemens AG, SanDisk | MMCmicro | 2005 | 4 GB | | Subcompact (14 mm × 12 mm × 1.1 mm), optional DRM, 16 MB to 4 GB |
| Nano Memory | proprietary (from Huawei) | | 2018 | 512 GB | | Subcompact (12.3 mm × 8.8 mm × 0.7) smallest dimensions as of 2024. Can use Nano-SIM slots. |
| Secure Digital | SanDisk, Panasonic, Toshiba, Kodak, SD Association | SD | 1999 | 2 GB | | Small (32 mm × 24 mm × 2.1 mm), DRM, up to 2 GB. (2 GB cards use larger block sizes and may not be compatible with some host devices. See Article) |
| Secure Digital | SanDisk, Panasonic, Toshiba, Kodak, SD Association | miniSD | 2003 | 2 GB | | Compact (15 mm × 11 mm × 1 mm), DRM, up to 2 GB. (2 GB cards use larger block sizes and may not be compatible with some host devices. See Article) |
| Secure Digital | SanDisk, Panasonic, Toshiba, Kodak, SD Association | microSD | 2005 | 2 GB | | Subcompact (15 mm × 11 mm × 1 mm), DRM, up to 2 GB. (2 GB cards use larger block sizes and may not be compatible with some host devices. See Article) |
| Secure Digital | SanDisk, Panasonic, Toshiba, Kodak, SD Association | SDHC | 2006 | 32 GB | | Same build as SD but greater capacity and transfer speed, 4 GB to 32 GB (not compatible with older host devices). |
| Secure Digital | SanDisk, Panasonic, Toshiba, Kodak, SD Association | miniSDHC | 2008 | 32 GB | | Same build as miniSD but greater capacity and transfer speed, 4 GB to 32 GB. 8 GB is largest in early-2011 (not compatible with older host devices). |
| Secure Digital | SanDisk, Panasonic, Toshiba, Kodak, SD Association | microSDHC | 2007 | 32 GB | | Same build as microSD but greater capacity and transfer speed, 4 GB to 32 GB. (not compatible with older host devices) |
| Secure Digital | SanDisk, Panasonic, Toshiba, Kodak, SD Association | SDXC | 2009 | 1 TB | | Same build as SD/SDHC, but greater capacity and transfer speed, 32 GB and higher. Standard goes up to 2 TB (not compatible with older host devices). |
| Secure Digital | SanDisk, Panasonic, Toshiba, Kodak, SD Association | microSDXC | 2009 | 2 TB | | Same build as microSD/microSDHC, but greater capacity and transfer speed, 32 GB and higher. Standard goes up to 2 TB (not compatible with older host devices). |
| Secure Digital | SanDisk, Panasonic, Toshiba, Kodak, SD Association | SDUC | 2018 | 4 TB | | Same build as SD/SDHC/SDXC, but greater capacity and transfer speed. Standard goes up to 128 TB (not compatible with older host devices). |
| SmartMedia | Toshiba | 3.3/5 V | 1995 | 128 MB | | Very slim (45.0 mm × 37.0 mm × 0.76 mm), no wear leveling controller, up to 128 MB. This particular example shows the write protect sticker (the silver disc). |
| Memory Stick | Sony, SanDisk | Standard | 1998 | 128 MB | | Slim and narrow (50 mm × 21.5 mm × 2.8 mm), optional DRM, up to 128 MB |
| Memory Stick | Sony, SanDisk | PRO | 2003 | 4 GB | (not to scale) | Slim and narrow (50 mm × 21.5 mm × 2.8 mm), swifter, optional DRM, up to 4 GB |
| Memory Stick | Sony, SanDisk | Duo | 2003 | 128 MB | | Compact (31 mm × 20 mm × 1.6 mm), optional DRM, up to 128 MB |
| Memory Stick | Sony, SanDisk | PRO Duo | 2002–2006 | 32 GB | | Compact (31 mm × 20 mm × 1.6 mm), optional DRM, up to 32 GB |
| Memory Stick | Sony, SanDisk | PRO-HG Duo | 2007–2008 | 32 GB | | Compact (31 mm × 20 mm × 1.6 mm), swifter, optional DRM, up to 32 GB |
| Memory Stick | Sony, SanDisk | Micro (M2) | 2006 | 16 GB | | Subcompact (15 mm × 12.5 mm × 1.2 mm), optional DRM, up to 16 GB |
| Memory Stick | Sony | PS Vita Memory Card | 2012 | 64 GB | | Subcompact (15 mm × 12.5 mm × 1.6 mm), compulsory DRM, up to 64 GB, proprietary (can be used on PS Vita only) |
| P2 (storage media) | Panasonic | MicroP2 | 2012 | 64 GB | | MicroP2 is a SDXC/SDHC card conforming to UHS-II (Ultra High Speed bus), and can be read by common SDHC/SDXC card readers. |
| xD | Olympus, Fujifilm, Sony | Standard | 2002–2007 | 512 MB | | Slim and small (20 mm × 25 mm × 1.78 mm), electrically identical to SmartMedia, no wear-leveling controller, up to 512 MB |
| xD | Olympus, Fujifilm, Sony | Type M | 2005 | 2 GB | | Slim and small (20 mm × 25 mm × 1.78 mm) but slower read/write, no wear-leveling controller, up to 2 GB |
| xD | Olympus, Fujifilm, Sony | Type H | 2005 | 2 GB | | Slim and small (20 mm × 25 mm × 1.78 mm) and swifter, no wear-leveling controller, up to 2 GB |
| XQD card | Sony & Nikon | Standard | 2011–2012 | 240 GB | | High-capacity, high-speed standard using PCIe as interface. Claimed max. allowed in spec is 2 TB (or over, but no product has come close to that). |
| Universal Flash Storage Card Extensions | Samsung | UFS Card | 2016 | >256 GB | | Packages the flash memory, currently soldered in shipping smartphones, into a removable card form factor. Uses the SCSI command set including queuing. The electrical interface makes use of differential signaling, which enables high bus speeds and robustness under noisy conditions and reduced pin count (compared to parallel bus alternatives such as UHS-I). |
| USB flash drive | Various | USB 1.1/2.0/3.0/3.1 | 2000/2001 | 8 TB | (not to scale) | Universally compatible across most non-mobile computer platforms, their greater size suits them better to file transfer/storage instead of use in portable devices |

## Physical details

Note that a memory card's dimensions are determined while holding the card with contact pins upwards. The length of cards is often greater than their width. Most cards show a directional arrow to aid insertion; such an arrow should be upward.
| Card | Width (mm) | Length (mm) | Thickness (mm) | Volume (mm³) | Mass (g) |
| CompactFlash, Type I | 43.0 | 36.0 | 3.3 | 5,108 | 3.3 |
| CompactFlash, Type II | 43.0 | 36.0 | 5.0 | 7,740 | |
| SmartMedia | 37.0 | 45.0 | 0.76 | 1,265 | 2.0 |
| MMC, MMCplus | 24.0 | 32.0 | 1.4 | 1,075 | 1.3 |
| RS-MMC, MMCmobile | 24.0 | 18.0 | 1.4 | 605 | 1.3 |
| MMCmicro | 14.0 | 12.0 | 1.1 | 185 | |
| SD, SDHC, SDXC, SDIO, MicroP2 | 24.0 | 32.0 | 2.1 | 1,613 | 2.0 |
| miniSD, miniSDHC, miniSDIO | 20.0 | 21.5 | 1.4 | 602 | 1.0 |
| microSD, microSDHC, microSDXC | 11.0 | 15.0 | 1.0 | 165 | 0.27 |
| Memory Stick Standard, PRO | 21.5 | 50.0 | 2.8 | 3,010 | 4.0 |
| Memory Stick Duo, PRO Duo, PRO-HG, XC | 20.0 | 31.0 | 1.6 | 992 | 2.0 |
| Memory Stick Micro (M2), XC | 12.5 | 15.0 | 1.2 | 225 | 2.0 |
| Nano Memory | 12.3 | 8.8 | 0.7 | 76 | |
| PS Vita Memory Card | 15 | 12.5 | 1.6 | 300 | 0.6 |
| XQD card | 38.5 | 29.8 | 3.8 | 4,360 | |
| xD | 25.0 | 20.0 | 1.78 | 890 | 2.8 |
| USB | varies | varies | varies | varies | varies |

## Speed comparison

| Standard | SD | SD | SD | SD | UFS Card | UFS Card | CFast | CFast | XQD | XQD | CFexpress | CFexpress |
| Version | 3.0 | 4.0 | 6.0 | 7.0 | 1.0/1.1 | 3.0 | 1.0 | 2.0 | 1.0 | 2.0 | 1.0 | ? |
| Launched | 2010 Q2 | 2011 Q1 | 2017 Q1 | ? | 2016 Q2 / 2018 Q1 | 2020 Q4 | 2008 Q3 | 2012 Q3 | 2011 Q4 | 2014 Q1 | 2017 Q2 | ? |
| Bus | UHS-I | UHS-II | UHS-III | PCIe | UFS 2.0 | UFS 3.0 | SATA-300 | SATA-600 | PCIe 2.0 x1 | PCIe 2.0 x2 | PCIe 3.0 x2 | PCIe 3.0 x8 |
| Speed (full-duplex) | 104 MB/s | 156 MB/s | 624 MB/s | 1970 MB/s (?) | 600 MB/s | 1200 MB/s | 300 MB/s | 600 MB/s | 500 MB/s | 1000 MB/s | 1970 MB/s | 7880 MB/s |

## Technical details

| Card | Varieties | Max storage capacity (nom. in GiB) | Theoretical max. capacity (nom. in GiB) | Max read speed (MB/s) | Max write speed (MB/s) | Read-write cycles | Low-level access | Operating voltage (V) | Controller chip | # of pins |
| CompactFlash | I | 512 | 128 PiB (134,217,728 GiB) | 167 | 167 | | NOR/NAND | 3.3 and 5 | Yes | 50 |
| CompactFlash | II | 12 | 128 PiB (134,217,728 GiB) | 167 | 167 | | NOR/NAND | 3.3 and 5 | Yes | 50 |
| SmartMedia | | 128 MiB (0.125 GiB) | | 2 | | 1,000,000 | NAND | 3.3 or 5 | No | 22 |
| MMC | MMC | 8 | 128 | 2 | 2 | 1,000,000 | NAND | 3.3 | Yes | 7 |
| MMC | RS-MMC | 2 | 128 | 2 | 2 | 1,000,000 | NAND | 3.3 | Yes | 7 |
| MMC | MMCmobile | 2 | 128 | 15 | 8 | 1,000,000 | NAND | 1.8 and 3.3 | Yes | 13 |
| MMC | MMCplus | 4 | 128 | 52 | 52 | 1,000,000 | NAND | 3.3 | Yes | 13 |
| MMC | MMCmicro | 2 | 128 | | | 1,000,000 | NAND | 1.8 and 3.3 | Yes | 10 |
| MMC | eMMC | | 2 TiB (2048 GiB) | 104 | 104 | | NAND | 1.8 and 3.3 | Yes | Varies |
| Secure Digital | SD (SDSC) | 512 | 4 | 25 | 25 | | NAND | 3.3 | Yes | 9 |
| Secure Digital | miniSD | 8 | 4 | 25 | 25 | | NAND | 3.3 | Yes | 11 |
| Secure Digital | microSD | 4 | 4 | 25 | 25 | | NAND | 3.3 | Yes | 8 |
| Secure Digital | SDHC | 32 | 32 | 104 (UHS-I) | 104 (UHS-I) | | NAND | 1.8 and 3.3 | Yes | 9 |
| Secure Digital | miniSDHC | 4 | 32 | 104 (UHS-I) | 104 (UHS-I) | | NAND | 1.8 and 3.3 | Yes | 11 |
| Secure Digital | microSDHC | 32 | 32 | 104 (UHS-I) | 104 (UHS-I) | | NAND | 1.8 and 3.3 | Yes | 8 |
| Secure Digital | SDXC | 512 | 2 TiB (2048 GiB) | 104 (UHS-I) | 104 | | NAND | 2.7–3.6 | Yes | 9 |
| Secure Digital | microSDXC | 1 TiB | 2 TiB (2048 GiB) | 104 (UHS-I) | 104 (UHS-I) | | NAND | 2.7–3.6 | Yes | 8 |
| Memory Stick | Standard | 128 MiB (0.125 GiB) | 128 MiB (0.125 GiB) | 2.5 | 1.8 | | NAND | 3.3 | Yes | 10 |
| Memory Stick | PRO | 4 | 2 TiB (2048 GiB) | 20 | 20 | | NAND | 3.3 | Yes | 10 |
| Memory Stick | PRO Duo | 32 | 2 TiB (2048 GiB) | 20 | 20 | | NAND | 3.3 | Yes | 10 |
| Memory Stick | PRO-HG Duo | 32 | 2 TiB (2048 GiB) | 30 (actual; theoretical: 60) | 30 (actual; theoretical: 60) | | NAND | 3.3 | Yes | 10 |
| Memory Stick | Micro (M2) | 16 | 32 | 20 | 20 | | NAND | 1.8 and 3.3 | Yes | 10 |
| Memory Stick | xC | | 2 TiB (2048 GiB) | 60 | 60 | | NAND | 3.3 | Yes | 10 |
| xD | | 512 MiB (0.5 GiB) | 512 MiB (0.5 GiB) | 5 | 3 | | NAND | 3.3 | No | 18 |
| xD | Type M | 2 | 8 | 4 | 2.5 | | NAND | 3.3 | No | 18 |
| xD | Type H | 2 | 8 | 5 | 4 | | NAND | 3.3 | No | 18 |
| xD | Type M+ | 2 | 8 | 6 | 3.75 | | NAND | 3.3 | No | 18 |
| XQD | | 64 | 2+ TiB (2+ GiB) | 168 | 168 | | NAND | 5 | | |
| USB | Full speed (USB 1) | 2048 (2 TiB) | No hardware limit | 1 | 1 | | NAND | 5 | Yes | 4 |
| USB | High speed (USB 2.0) | 2048 (2 TiB) | No hardware limit | 40 | 40 | | NAND | 5 | Yes | 4 |
| USB | Super speed (USB 3.0) | 2048 (2 TiB) | No hardware limit | 240 | 160 | | NAND | 5 | Yes | 4 |

## Consumer details

| Card | Write protection switch | DRM |
| CompactFlash | No | No |
| SmartMedia | Partial, sticker | Partial (optional) |
| MMC, RS-MMC | No | No |
| MMCMobile | No | Yes, secureMMC |
| SD | Yes | Yes, CPRM |
| miniSD | No | Yes, CPRM |
| microSD | No | Yes, CPRM |
| Memory Stick Standard, PRO | Yes | Optional, MagicGate |
| Memory Stick Duo, PRO Duo | No | Optional, MagicGate |
| Memory Stick PRO-HG Duo | No | Optional, MagicGate |
| Memory Stick Micro (M2) | No | Optional, MagicGate |
| PS Vita Memory Card | No | Yes, Proprietary |
| xD | No | Partial |
| USB | Sometimes | No |

## Compatibility

The following chart gives details on availability of adapters to put a given card (horizontal) in a given slot or device (vertical). This table does not take into account protocol issues in communicating with the device.
Following labels are used:
* + (native) – A slot is native for such card.
* D (Directly compatible) – A card may be used in such a slot directly, without any adapters. Best possible compatibility.
* M (requires a Mechanical adapter) – Such adapter is only a physical enclosure to fit one card sized into another; all electrical pins are exactly the same.
* EM (requires an Electro-Mechanical adapter) – Such adapter features both physical enclosure and pins re-routing as terminals are sufficiently different. No powered elements in such adapter exists, thus they're very cheap and easy to manufacture and may be supplied as a bonus for every such card.
* E (requires an Electronic adapter enclosure) – These adapters must have components—potentially requiring external power—that transform signals, as well as physical enclosure and pin routing.
* X (requires an eXternal adapter) – Technically the same as E, but such adapter usually consists of 2 parts: a pseudo-card with pin routing and physical enclosure size that perfectly match the target slot and a break-out box (a card reader) that holds a real card. Such adapter is the least comfortable to use.
* XM (requires an eXternal electro-mechanical adapter) – Technically the same as EM, but such adapter usually consists of 2 parts: a pseudo-card with pin routing and physical enclosure size that perfectly match the target slot and a break-out box (a card reader) that holds a real card. Such adapter is the least comfortable to use.
* Empty cell – Card cannot be used in such slot, no single adapter is known to exist. Sometimes a chain of adapters can help (for example, miniSD→CF as miniSD→SD→CF).
| CardSlot | CF | CF | CFast | SM | MMC | MMC | Memory Stick | Memory Stick | Memory Stick | Memory Stick | SDSC | SDSC | SDSC | SDHC | SDHC | SDHC | SDXC | SDXC | xD | xD | xD | XQD |
| CardSlot | I | II | | | MMC | RS-MMC, MMCmobile | Std | PRO | PRO Duo | Micro | SDSC | miniSD | microSD | SDHC | miniSDHC | microSDHC | SDXC | microSDXC | Std | M | H | |
| ExpressCard | E | E | | | E | | E | E | E | | E | E | E | | | | | | E | E | E | EM |
| PCI Express Mini Card | | | | | | | | | | | | | | | | | | | | | | EM |
| mSATA | | | XM | | | | | | | | | | | | | | | | | | | |
| PC Card | EM | EM | | E | E | | E | E | | | E | | | | | | | | | | | |
| PCMCIA | EM | EM | | E | E | | E | E | | | E | | | | | | | | | | | |
| CF I | + | + | | E | E | | E | E | E | | E | | | | | | | | E | E | E | |
| CF II | | + | | E | E | | E | E | | | E | | | | | | | | E | E | E | |
| CFast | | | + | | | | | | | | | | | | | | | | | | | |
| SM | | | | + | | | | | | | | | | | | | | | X | X | X | |
| xD | | | | | | | | | | | | | E | | | | | | + | + | + | |
| XQD | | | | | | | | | | | | | | | | | | | | | | + |
| MMC | | | | | + | M | | | | | D | | | | | | | | | | | |
| MS | | | | | X | | + | + | M | M | X | X | E | | | | | | | | | |
| SDSC | | | | | D | M | | | | | + | EM | EM | | | | | | | | | |
| miniSD | | | | | | | | | | | | + | EM | | | | | | | | | |
| microSD | | | | | | | | | | | | | + | | | | | | | | | |
| SDHC | | | | | | | | | | | D | EM | EM | + | EM | EM | | | | | | |
| miniSDHC | | | | | | | | | | | | D | EM | | + | EM | | | | | | |
| microSDHC | | | | | | | | | | | | | D | | | + | | | | | | |
| SDXC | | uscb | | | | | | | | | D | EM | EM | D | EM | EM | + | EM | | | | |
| microSDXC | | | | | | | | | | | | | D | | | D | | + | | | | |
| IDE PATA | EM | EM | | | | | | | | | E | | | | | | | | | | | |
| Serial ATA | E | E | EM | | | | | | | | | | | | | | | | | | | |
| PCI Express | | | | | | | | | | | | | | | | | | | | | | EM |
| USB | X | X | | X | X | | X | X | E | E | E | | E | | | | | | X | X | X | X |
| Floppy | | | | E | E | E + M | E | E | | | | | | | | | | | | | |
| Nintendo DS Slot-1 | | | | | | | | | | | | | E | | | | | | | | | |
| Nintendo DS Slot-2 | | | | | | | | | | | E | E | E | | | | | | | | | |