Flash Memory in a Fingernail: Understanding Samsung Secure Digital Memory Cards

Flash Memory in a Fingernail: Understanding Samsung Secure Digital Memory Cards 

If you’ve ever been confused about the difference between a microSD Card PRO Ultimate and EVO Plus, this illustrated guide to memory cards will teach you everything you need to know. 

Smartphones, tablets, handheld gaming consoles, drones, dash cams, video cameras, and even VR headsets. No matter what consumer gadget you’re talking about, there’s a good chance they contain a postage stamp or fingernail-sized chip of NAND flash memory that allows you to expand their storage capacity. But how does this technology work, and what makes one memory card different from another? 

In this month’s Heart of Tech, we’re doing a deep dive into the flash storage technology used in Samsung Memory’s SD and microSD memory cards. We’ll teach you about the innovative NAND flash memory technology behind Samsung memory cards, how Samsung is innovating in the product category, and how an informed consumer can choose the right memory card for them, even without knowing the difference between different brand line-ups. 

Understanding Memory Cards 

The ‘SD’ in both SD and microSD refers to ‘Secure Digital’, a flash memory card format that was originally developed by the multibody SD Association back in 2000. This standard has undergone many revisions and updates since 2000, but what all Secure Digital memory cards have in common is they are made of a miniature processor and at least one chip of NAND flash memory.  

Since 2003, Samsung Semiconductor has been recognized as the world’s #1 brand of flash memory, largely due to the incredible technological innovation it has brought to bear on the problem of improving secure digital memory cards. For example, in 2013, Samsung introduced the world’s first V-NAND (or vertical NAND) flash memory, which it has since integrated into products like the PRO Ultimate line of memory cards. By stacking memory layers on top of one another, V-NAND memory technology allows for memory cards that have much greater durability and performance, packed into a high-capacity package that used to only be possible in SSDs. 

Because of innovations like this, Samsung is widely recognized today as an industry leader in fast, reliable memory card technology. In a sea of competitors, Samsung Memory Cards are a brand that can be trusted. 

What To Look for in a Memory Card 

One of the factors that often confuses consumers when they shop for a new memory card is they all look roughly the same. But all memory cards are not created equal, even when manufactured by the same company: for example, our PRO Ultimate line of memory cards is a better fit for performance-minded creators, while our PRO Endurance line is ideal for use in dash cams that require extensive write performance. But how can you tell? 

To understand what a memory card is capable of, just look at what’s written on it. They might look like hieroglyphics at first, but printed on every memory card are symbols that can tell you briefly what its capabilities are, and what it is good for. Learn to decode these symbols and you’ll be able to quickly tell at a glance what microSD Card to buy for your next smartphone, or SD Card you need for your DSLR. 

As a primer to the sometimes confusing world of memory card specifications, we’re going to walk you through the symbols on the Samsung 1TB microSD Card PRO Plus. Think of it like a Rosetta Stone for understanding the wide world of flash memory card symbols, specs, and standards. 

A Dictionary of Memory Card Symbols

1) Capacity – This number stands for the capacity of the memory card, or how many bytes of memory it contains. Modern memory cards usually come in capacities between 64GB and 1TB. 

2) Brand Name – Memory cards with similar performance capabilities are grouped under their own unique brand names and are usually marketed towards specific use scenarios. 

3) SD Specification – There have been many updates to the microSD Card and SD Card standard over the years, adding additional capacity. Two of the most recent standards are SDHC (Secure Digital High Capacity) and SDXC (Secure Digital eXtended Capacity), the latter of which maxes out at 2TB of capacity. The new SDUC (Secure Digital Ultra Capacity) supports capacities as large as 128TB, although there are no cards with that capacity on the market yet.

4) UHS Bus Speed – The UHS Bus Speed refers to the transfer speeds a memory card is capable of. The higher the class number, the faster you will be able to transfer data to and from the memory card. UHS-I offers maximum speeds up to 104MB/s, UHS-II affords maximum speeds up to 312MB/s, and UHS-III up to 624MB/s. Currently, most applications for SD memory cards are UHS-I based, but some cameras need higher speed UHS-II or UHS-III cards. Under certain circumstances, Samsung UHS-I cards provide up to 200MB/s through custom firmware. 

5) UHS Speed Class – Don’t confuse this number-in-a-bucket pictogram with UHS Class Speed. Whereas the former refers to maximum read/write speed, this number refers to minimum speed, and comes in two flavors: U1 and U3, or 10MB/s and 30MB/s, respectively. 

6) Application Performance Speed – This marking shows how a memory card performs when running apps. A1 devices sustain minimum random read/write speeds of up to 1500/500 IOPS, and minimum sustained sequential writes up to 10MB/s. Class A2 devices boost the minimum random read/write speeds to 4000/2000 IOPS.  

7) Video Speed Class – This symbol says how well a memory card can handle higher resolution video and recording features. The number following the V always refers to the minimum video write speed in MB/s. For example, a V30 video speed class indicates a minimum write speed of 30MB/s. 

Conclusion

Once you know what you’re looking for in a memory card, it’s easy to find the Samsung brand SD Card or microSD Card that is right for you.  

For example, if you’re a video editor who needs an SD Card, you’re probably going to care most about video speed class and UHS Bus Speed, which is why you should consider the SD Card PRO Ultimate. Looking for a high-performance microSD card for your handheld gaming console? You’ll want to look for capacity and application performance speed, which is why either the microSD Card PRO Plus or microSD Card EVO Plus is the right choice for you. 

No matter which card you get, though, rest assured. When you buy a Samsung SD Card or microSD Card, you’re getting a memory card you can trust. You’re getting nothing less than a high-tech, snowflake-sized wafer of the world’s #1 flash memory. 

Heart of Tech is a series of themed monthly articles from Samsung Semiconductor about how our technologies are transforming the world. Follow our LinkedIn and never miss an update.