miniSD microSD SD Card Review

SD Card

Compact and Powerful, Ideal for Small Products

The SD memory card measures a mere 24mm x 32mm x 2.1mm approximately the size of a typical postage stamp. The slim, compact design promotes easy handling, an important factor for a "bridge media" that can be moved between different products. Using decoder software, an SD compatible device can play music, video clips and more without a drive mechanism like those in CD and DVD players. This allows the equipment to be more compact and gives product designers new creative freedom. Reliability is also improved through the elimination of skipping on music and video files.

Simplified Version of Physical Layer Specification

	SD
Size
Area	768 mm2 (100)
Card Volume	1,613 mm3 (100)
Thickness	2.1 mm
Weight	Approx. 2g
Number of pins	9 pins
Operating Voltage	2.7V - 3.6V
Write-protect Switch	YES
Copyright protection	CPRM
Compatibility	-
Capacity	Up to 2 GB

miniSD Card

Smaller Size Offering the Same Power, Reliability and Speed as the SD Card

The miniSD card standard was developed to meet continuing industry demands for smaller mobile phones. The miniSD is just 37 percent of the SD card's size, and it packs all of the storage power, speed and other benefits into a small card - including copyright protection. By inserting the miniSD card into a miniSD adapter, you can share a variety of digital data among full-size SD card-enabled products.

	miniSD
Size
Area	430 mm2 (56)
Card Volume	602 mm3 (37)
Thickness	1.4 mm
Weight	Approx. 1g
Number of pins	11 pins
Operating Voltage	2.7V - 3.6V
Write-protect Switch	NO
Copyright protection	CPRM
Compatibility	Yes (with adapter)
Capacity	Up to 2 GB

microSD Card

Smallest Size Card Featuring the Power, Reliability and Speed of the SD Card

Like the miniSD card, the microSD card standard was specifically designed for the ever-changing and fast- growing mobile market. Approximately the size of a fingernail, it is even smaller than the miniSD card and about one-fourth the size of a full-size SD card.

	microSD
Size
Area	165 mm2 (21)
Card Volume	165 mm3 (10)
Thickness	1.0 mm
Weight	Approx. 0.5g
Number of pins	8 pins
Operating Voltage	2.7V - 3.6V
Write-protect Switch	NO
Copyright protection	CPRM
Compatibility	Yes (with adapter)
Capacity	Up to 2 GB

Wide Market Adoption

The microSD and microSDHC are the leading memory card standards adopted by mobile handset vendors because of their ultra-compact size and widely supported standard SD interface.

Although primarily used with mobile phones, the microSD standard also is supported natively in a variety of hand-held GPS devices, portable audio players, video game consoles, expandable USB flash memory drives and computer tablets.

Compatibility and Interoperability

All microSD memory cards are backward compatible with SD standards-enabled electronic devices. By using an appropriate adapter, the microSD memory card can easily and quickly be inserted into any device that supports a full-size SD or miniSD memory card.

SD Speed Class/UHS Speed Class

Greater Performance Choices

There are two kinds of Speed Class, "Speed Class" and "UHS Speed Class."

As a characteristic of flash memory, actual transfer speed varies. Variable speeds are difficult to reliably record streaming content such as video because it requires a constant writing speed. Speed Class and UHS Speed Class provide the constant speed necessary for video recording by designating a minimum writing performance so that minimum and constant speed is guaranteed for camcorders, video recorders and other devices with video recording capabilities under the conditional write operation specified in the standard.

Speed Class, designated as Class 2, 4, 6 and 10, is designed for normal and high speed bus interface (mode) and UHS Speed Class 1 is designed for UHS bus interface*. (Speed Class and the UHS Speed Class are not compatible.)

*UHS (Ultra High Speed), the fastest performance category available today, defines bus-interface speeds up to 312 Megabytes per second for greater device performance in SDXC and SDHC devices.

	Marks	Operable Under...	Applications	SD Memory Card
Speed Class		Normal Bus I/F	SD video recording	SD, miniSD, microSD SDHC, miniSDHC, microSDHC SDXC, microSDXC
			HD ~ Full HD video recording
		High Speed Bus I/F	Full HD video recording HD still consecutive recording
UHS Speed Class		UHS-I Bus I/F	Full higher potential of recording real-time broadcasts and capturing large-size HD videos	SDHC UHS-Iand SDXC UHS-I

UHS Speed Class Compatibility

Speed Class Compatibility

Fragmentation and Speed

The memory of a card is divided into minimum memory units. The device writes data onto memory units where no data is already stored. As available memory becomes divided into smaller units through normal use, this leads to an increase in non-linear, or fragmented storage. The amount of fragmentation can reduce write speeds, so faster SD memory card speeds help compensate for fragmentation.

The SD Association developed standards specifying operating conditions for SDHC, SDXC, SDHC UHS and SDXC UHS memory cards to guarantee the minimum speed according to the card's speed class. Speed logos are provided to help identify cards that comply with these standards.