Choosing correct SD and microSD card for professionals

Quality of photos taken with modern smartphones is comparable to those which, not long ago, were made with high-end DSLR cameras while recording 4K videos is a standard feature of every flagship product. Currently the resolution of camera sensors has exceeded 50 Mpix, allowing cam-eras to take photos that take over 100 MB of space. At the same time all new cameras are able to perform continuous shooting with speed of several dozen photos per second. Professional camer-as can easily record 8K resolution or slow motion 240 frame-per-second videos, yielding files as big as 200 MB per second.
This, combined with environmental challenges that prosumers and creative professionals face, requires manufacturers of storage products, to design products that are fast, capacious, robust and reliable enough to meet all these demands.

Understanding symbols on memory cards

SD and microSD memory cards have a number of markings that allow to identify their speed and compatibility with the host device. Symbols on cards are based on standards defined by the SD Association and they change along with technology development.
Below explanation is based on microSD card for professional applications.


Symbols which appear on IRDM PRO microSD card.

Standard – Defines the physical size of memory card (SD or microSD) and its capacity – cards ranging from 4 to 32 GB are marked as High Capacity (HC) and from 64GB to 2 TB as Extended Capacity (XC). Host de-vice needs to be able to support corresponding standard. Host devices are backwards compatible – if it supports SDXC, then SDHC and SD are supported as well.
UHS Bus Mark – defines maximum throughput of memory card. Currently available interfaces are: UHS I (through-put of up to 104 MB/s) and UHS II (throughput of up to 312 MB/s). To reach maximum throughput of card, the host device must support the given standard. Just like with the above, host devices are backwards compatible.
UHS Speed Class – defines minimum sequential write speed – 10 MB/s for UHS Speed Class U1 and 30 MB/s for UHS Speed Class U3.
Video Speed Class – a minimum random write speed, in the range of 6MB/s (V6) to 90 MB/s (V90). As the name says, this speed class is especially important for video-oriented applications as it takes into account ran-dom write speed, unlike standard speed class that defines sequential write speed.
Speed Class– thus far the most popular mark defining the card parameters. The class value is equivalent to guar-anteed minimum sequential write speed in MB/s (e.g., class 4 means the memory card will write the data sequentially with speed no lower than 4 MB/s ). According to the newest SD Association specification, as long as the Video Speed Class and UHS Speed Class are marked, there is no need to put Speed Class symbol on memory cards.

Speed is not everything – parameters important for professionals

Apart from the above features, memory cards have additional set of parameters which significantly affect their practicality. They relate to endurance and reliability and can be classified as below:

Memory card mustn’t fail in harsh environmental conditions.

Resistance for environmental factors: X-ray radiation, water and shock resistance.
Operating and storage temperature: the range of the temperatures in which the memory card will correctly process and store the data during operation and storage.
Endurance: the amount of the data which can be written on the memory card during its lifetime.

Resistance for environmental factors includes a wide range of features that may be useful in situa-tions which, apparently, should not harm the memory card. It includes accidental soaking, x-ray scan during security check at the airport or dropping camera during recording.
Extended range of operating and storage temperatures can prove valuable in extremely cold or hot places. Standard memory cards usually guarantee a proper work in the range of 0 to 70°C which may be insufficient for many professionals. It is worth to consider purchasing a card, that ensures undisturbed work and allows to store the data in a full temperature range, ie. from -45° to 85°C.
NAND flash memory technology restricts the endurance to specific number of data writes. De-pending on quality and technology of used component, the endurance may vary even up to hun-dred times. Keeping in mind how much room is taken by the 4K/8K quality videos or photos in RAW format it is worth to invest in memory card based on the best quality components produced in relevant technology.

Which memory card I should choose?

Up till now the selection of memory cards for professional use was not the easiest choice. The mul-titude of numbers, marks and parameters defining minimum and maximum speeds, compatibility, endurance, resistance for environmental factors not only hinder the purchase but frequently end-ed up where the only solution was getting several products and using them depending on the needs and situation. GOODRAM IRDM and GOODRAM IRDM PRO SD and microSD memory cards fulfill all the needs of modern, digital professionals regardless of used hardware and designated purpose. They are suita-ble for high quality continuous shooting as well as recording and processing 4K and 8K videos. In addition IRDM and IRDM PRO SD cards prove as a good memory extension for flagship smartphones and computers with built-in memory card slots.

Main features of IRDM memory cards are:
Highest maximum speed of 280 MB/s for read and up to 240 MB/s for write.
Maximum guaranteed random write speed of 90 MB/s, in line with the highest Video Class Speed (V90).
Resistance for harsh conditions: water, shock, drops, X-ray radiation.
Capacity up to 256 GB, sufficient to store hours of material and thousands of photos.
Unmatchable endurance with usage of MLC (IRDM) and pSLC NAND Flash (IRDM PRO), cards can have up to 100 times higher endurance vs. standard consumer memory cards.
Lifetime warranty and technical support directly from the manufacturer.


SD Logo, SDHC Logo, microSD Logo, and microSDHC Logo are trademarks of SD-3C, LLC.
Performance and endurance values are based on internal tests and may vary depending on the testing procedures and use.
Some products may have an associated image or photo. These are for reference only and should be considered illustrative.