Flash memory is a complex technology, and cards are made to different quality standards for different tasks. The markings on cards are standardised by the SDA Association and are designed to help users buy cards with the technical specification that meets their needs. Markings refer to a number of discrete qualities on cards. Examples are: the maximum read speeds and maximum sequential write speeds (higher speeds will be useful for applications such as digital video); and different card formats which have changed as the medium has developed. We have an Explainer which goes into this in more detail.
As with many things, an apparent bargain should be viewed with scepticism. SD cards which look like they are from reputable makers but which are lower in price than you would expect could be fake. Cards from makers which don’t have a well established reputation could be fake, or even just a plastic chassis with nothing inside. Even reputable online generalist sellers can have such cards available from fake sellers. Always check the web sites of card makers to learn about their range, and consider buying direct where you can. Buyer beware – by the time you learn about an issue, it may be too late as your vital data could be lost.
Flash memory cards branded by well-known companies bring the user a guarantee of performance and quality to the level stated by markings on the card. There are many cards branded with lesser known names available online, often at much lower prices. These are often fake cards, which are unreliable or might even fail to work at all. For peace of mind in storing your valuable data, it is always worth opting for a well-known and trusted brand.
Flash memory is designed to make file copies that are identical to the source. Commercial copying to hundreds or even tens of thousands of flash memory cards benefits from a process called bit-by-bit duplication. This is what we use at Cardwave, and there is more information about it here. However flash memory is only good for a certain number of read / write actions, and when a card degrades the data stored on it will be lost, and the card might fail completely at any time. It is always important to back up important data stored on flash memory.
Some SD memory has to withstand very challenging conditions like extremes of temperature including desert heat and sub-zero, and significant vibration or shock. Typical usage includes settings like healthcare, aerospace, and even military. In the manufacturing process some memory will come out of the same production process at a higher quality, and this is identified and tested, then certified as able to meet harsher conditions. We discuss this further in a blog post about different grades of flash memory.
SD cards are designed to make exact copies of the source data, and this does not change with different card capacities. However, beware of low quality or fake SD cards which may be made from poor quality materials or not function as advertised. Such cards may fail to save exact copies of source data, or fail to work at all.
SD cards are often sold to the general public without any security built in. However there are tools for encrypting the data stored on cards, specific applications can have password protection, and there are card readers and USB flash drives with built in biometrics such as fingerprint security. If no security measures are in place, anyone who finds your lost flash memory device will be able to read the contents. It is also worth noting that some types of password protection are more crackable than others.
With high quality biometric and two-factor authentication the data on an SD card can be as secure as the data on your laptop. Specialist providers focus on this level of security, which can include remote wipe or ‘self-destruct’ of data if a drive is compromised or there are failed password attempts.
It is an unfortunate truth that the makers of SD cards are often the target of unscrupulous firms who use their logo and card design to sell sub-standard products at low prices. The customer may think they are getting a bargain, but these often well-disguised fakes are very far from value for money lacking the quality, specifications and longevity of legitimate cards. Popular online stores are a preferred outlet of fake SD card sellers.
Different SD cards can read and write data at different speeds. This makes them suitable for different uses. Someone wanting to record 8K video will need a card with a video speed class of V90, while someone wanting to record 4K video needs a video speed class of V60. Meanwhile someone wanting to save data files such as documents could use a card capable of 10MB a second, which is a V10 speed class. There are also classifications for data transfer (based on the BUS interface), and for sequential read / write (based on the guaranteed sequential read / write speed). So an SD card is as fast as the user needs it to be.
There is no precise answer to this question because it relates to the type and grade of memory used. As a guide, a consumer grade card should last long enough to fill the entire card up at least 500 times – which is plenty for the average consumer. An industrial grade card however should have more advanced firmware and this will manage the data write process more efficiently. Industrial grade cards should be good for 3000 P/E cycles.
USB3.0 flash drives are backward compatible with USB2.0 card readers. However, if you put a USB3.0 flash drive into a USB2.0 card reader, it will only be able to operate at USB2.0 speed.
Yes we can. Cardwave has pioneered a unique process with our manufacturing partner for encrypted drives so we can offer a mass duplication process
Flash memory has come a long way since its invention in the 1980s. Advances in technology have allowed flash memory cards to become smaller while storing more data, to develop faster read / write times, and to become more robust, with cards now available for harsh conditions such as extremes of temperature and shock. The development cycle continues, and flash memory looks set to keep pace with storage needs for many years to come.
Flash memory comes in a range of sizes, both in formats designed to be embedded in devices and in removable formats which are designed to be accessed by the user. microSD is the smallest removable flash memory format. It measures 15mm x 11mm x 1mm thick. It is technically possible to produce smaller removable flash memory. In 2018 Huawei launched its NanoMemory cards, which are the same size as a nano SIM at 12 mm x 9 mm x 1 mm thick. A key selling point was its potential for smartphones, but the format did not gain wide support. A key factor affecting how small removable flash storage can get is human capability to handle cards.
Your phone will probably send photos and video to cloud storage backup by default. Some people prefer to have a local backup instead of cloud, or to have a local backup in addition to cloud. To back up data from a phone to your computer you can download it from the cloud storage. Alternatively specialist flash memory based photosticks can search a phone’s internal storage for images and videos and make a backup. It’s easy to back this stick up to your computer, effectively providing two local backups that can’t be affected if cloud storage is compromised. Just remember to make a backup to the photostick regularly. Photosticks can be biometric to help secure your precious images and videos.
SD cards store data in sections called blocks or sectors. A bad block or sector is an area of storage which for some reason is not able to store data. All flash memory has some bad blocks or sectors when it comes out of manufacturing. They can also develop over time through wear and tear. The better quality the product, the more likely it will have software on board to manage the issue, so that data does not become irretrievably lost. However, if an SD card does fail, its data won’t be accessible. For this reason it is important not to make an SD card the only place you keep important data. Always have a backup that can be restored if a card becomes unusable due to bad blocks or other reasons.
Wear levelling is a technology used on higher grade SD cards and Solid State Drives (SSDs). Software within the controller monitors how frequently each block or sector is used either by data being stored to it or erased from it. The software ensures new data is written to blocks or sectors with the lowest number of accesses. This creates an even pattern of use across the whole card, helping to extend its life.
PE stands for Program Erase. The PE Cycle is the sequence of write, erase, write actions performed on the memory. The number of PE Cycles any one flash drive can accommodate is finite, and there are different technologies used in drive manufacture which affect the number. Enterprise-grade MLC (or E-MLC) accommodates around 30,000 PE Cycles per block, while Single-Level Cell (SLC) accommodates up to around 100,000 PE Cycles per block. SLC devices should last longer than E-MLC devices, and are also more expensive.
Bit-by-bit duplication copies the binary data from a master to another card. It is a process that guarantees the integrity of the copied data. It is a complex subject so please refer to our Explainer Why we use bit-by-bit duplication for more information.
Learn moreThe flash memory used in both embedded and removable products is largely the same, but the interface to the host device will be different. There are many other differences between embedded and removable memory and these are covered in our Explainer embedded vs removable flash memory.
Learn moreThe SD Association creates and evolves SD standards used by card and host device manufacturers. When makers join the SD Association, they agree to abide by the technical standards it sets, and to use a set of standardised marks on their cards. These standards help customers compare products from different manufacturers against a clearly defined set of benchmarks. Without these it would be difficult to compare cards from different makers. However there are many companies which are not members of the SD Association selling their products online. It can be difficult to assess or compare products from these companies without specialist knowledge.
Yes we do. Cardwave works with companies all over the world and our account managers are happy to work to different time zones when supporting international customers
Most orders are completed between 3 and 7 days, it largely depends on the volume and complexity of the job
Cardwave has accounts with the world’s leading manufacturers. We can place orders directly with them, and order inventory well in advance so customer needs are met in a timely way.
The warranty is manufacturer specific, as it is for the manufacturer to guarantee the quality of its product. Most manufacturers will offer a 12 month conditional warranty, but the high-end, industrial grade products we supply will have a longer warranty.
There are many different ways to send your master data to us. We operate a secure FTP portal and can create a unique login for you, or we can access your FTP site. If your master data is small enough we are happy to accept it by email or on a storage device such as a DVD, SD card or USB flash drive. We’ll work to the system that works best for you.
Mastering is an important part of our process because it establishes the criteria for the images we are replicating. Mastering is not just about the data, in encompasses the configuration of the flash memory storage device prior to the data being replicated and because some devices have unique configuration settings, this process is critical. Once a master has been approved by our customer the production process is guaranteed to replicate the exact image across however many instances you require. Find out more about terminology in our Explainer Flash memory terms explained.
Cardwave is based in the South West of England, about an hour directly west of London Heathrow airport in the historic county of Wiltshire
Cardwave complies with national and international standards that determine quality standards for operational performance and environmental reporting and compliance. Learn more in our Explainer Cardwave’s certifications and compliance.
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