This table provides summary of comparison of various flash memory cards, . 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 4 TB max. currently available, and the spec allows up to 128 max.), 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 8 TB.
Common information
Unless otherwise indicated, all images are to scale.
Card family Standards organizations Varieties Entry date Maximum commercially available capacity PicturePictures are given in relative scales; they're sized to be WYSIWYG when viewing using 81 PPI monitor. Main features CompactFlash SanDisk I 1994 512 GB (CF5 Thinner (3.3 mm), flash only, now up to 512 GB, although standard goes up to 128 PB since CF 5.0CompactFlash Association announces CF 5.0 standard supporting up to 128 PiB of storage II Thicker (5.0 mm), older flash, but usually Microdrives, up to 128 PiB –ATA and PC Card-compatibleCFexpressCompactFlash 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 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 – – – – 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 RS-MMC/MMC Mobile 2003/2005 16 GB Compact (24 mm × 18 mm × 1.4 mm), up to 16 GB MMCplus 2005 16 GB Compact (24 mm × 32 mm × 1.4 mm), swifter, optional DRM, up to 16 GB 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) 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) 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) 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). 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). 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) 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). 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). SDUC 2011 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/FTL 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 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 Duo 2003 128 MB Compact (31 mm × 20 mm × 1.6 mm), optional DRM, up to 128 MB PRO Duo 2002–2006 32 GB Compact (31 mm × 20 mm × 1.6 mm), optional DRM, up to 32 GB PRO-HG Duo 2007–2008 32 GB Compact (31 mm × 20 mm × 1.6 mm), swifter, optional DRM, up to 32 GB Micro (M2) 2006 16 GB Subcompact (15 mm × 12.5 mm × 1.2 mm), optional DRM, up to 16 GB 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)PanasonicP2200464 GBPC card containing several SD cards grouped together by a LSI Corporation RAID card MicroP2 2012 64 GB MicroP2 is an ordinary 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 MBFUJIFILM Global | xD-Picture Card and Adapters 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 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 2010 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)Plexus Outbursts specifications 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 1.3Apacer's MMC specifications 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 StandardSDUFS CardCFastXQDCFexpressVersion3.04.06.07.01.0/1.13.01.02.01.02.01.0?Launched2010 Q22011 Q12017 Q1?2016 Q2 / 2018 Q12020 Q42008 Q32012 Q32011 Q42014 Q12017 Q2?BusUHS-IUHS-IIUHS-IIIPCIeUFS 2.0UFS 3.0SATA-300SATA-600PCIe 2.0 x1PCIe 2.0 x2PCIe 3.0 x2PCIe 3.0 x8Speed (full-duplex)104 MB/s156 MB/s624 MB/s1970 MB/s (?)600 MB/s1200 MB/s300 MB/s600 MB/s500 MB/s1000 MB/s1970 MB/s7880 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)Voltage table at All Memory Cards, note that some cards support both voltages (and), and some cards are available in distinct versions (or) Controller chip # of pins CompactFlash I 512 128 PiB(134,217,728 GiB) 167CompactFlash Specification Rev. 6.0 167 NOR/NAND 3.3 and 5 rowspan="2" 50 II 12 128 PiB(134,217,728 GiB) 167 167 SmartMedia 128 MiB(0.125 GiB) 2 1,000,000 NAND 3.3 or 5 22 MMC MMC 8 128 2 2 1,000,000ACP-EP Specifications 3.3 rowspan="5" 7 RS-MMC 2 2ACP-EP RS-MMC card features list 2 3.3 7 MMCmobile 2 15ACP-EP MMCmobile card features list 8 1.8 and 3.3 13 MMCplus 4Transcend MMCplus 4 GiB 52MMC transferred at up to 52 MiB/s 52 3.3 13 MMCmicro 2 1.8 and 3.3 10Transcend MMCmicro card (TS128MMCM) datasheet eMMC 2 TiB(2048 GiB) 104 104 1.8 and 3.3 rowspan="1" Varies Secure DigitalMaximum transfer speed is not defined by SD standards. Bus speeds are quoted. SD (SDSC)512 4 25 25 3.3 rowspan="3" 9 miniSD 8 25 25 11 microSD 4 25 25 8 SDHC 3232 104 (UHS-I) 104 (UHS-I) 1.8 and 3.3 rowspan="3" 9 miniSDHC 4New 4 GiB miniSDHC card 104 (UHS-I) 104 (UHS-I) 11 microSDHC 32 104 (UHS-I) 104 (UHS-I) 8 SDXC 512 2 TiB(2048 GiB) 104 (UHS-I) 104 2.7–3.6 rowspan="2" 9 microSDXC1 TiB 104 (UHS-I) 104 (UHS-I) 8 Memory Stick Standard 128 MiB(0.125 GiB) 128 MiB(0.125 GiB) 2.5 1.8 3.3 rowspan="6" 10 PRO 4 2 TiB(2048 GiB) 20 20 3.3 PRO Duo 32 20 20 3.3 PRO-HG Duo 32http://www.sonystyle.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10551&storeId=10151&langId=-1&productId=8198552921666322869&tab=featuresTab 30 (actual;Sony Introduces Faster MS Pro HG Duo Card theoretical: 60) 30 (actual; theoretical: 60) 3.3 Micro (M2) 16 32 20 20 1.8 and 3.3 xC 2 TiB(2048 GiB) 60 60 3.3 xD 512 MiB(0.5 GiB) 512 MiB(0.5 GiB) 5 3 3.3 rowspan="4" 18 Type M 2 8 4 2.5 Type H 2 8 5 4 Type M+ 2 8 6 3.75 XQD 64 2+ TiB(2+ GiB) 168 168 5 USB Full speed (USB 1) 2048(2 TiB) No hardware limit 1 1 5 rowspan="3" 4 High speed (USB 2.0) 40 40 Super speed (USB 3.0) 240 160
Consumer details Card Write protection switch DRM CompactFlash SmartMedia , sticker (optional) MMC, RS-MMC rowspan="2" MMCMobile , secureMMC SD Some early SD cards may not have a write protection switch.The write protect switch signals to the host, which is responsible for write protection. The write protect switch is not connected to the internal circuitry of the card. (SD Card Simplified Physical Layer Specification ) rowspan="3" , CPRM miniSD microSD Memory Stick Standard, PRO , MagicGate Memory Stick Duo, PRO Duo , MagicGate Memory Stick PRO-HG Duo , MagicGate Memory Stick Micro (M2) , MagicGate PS Vita Memory Card , Proprietary xD USB Sometimes
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.