Samsung is currently testing a new range of microSD cards based on the so-called SD Express (SD XC EX) standard. Samsung promises faster read speeds than those of current (micro)SD cards. This would theoretically make them suitable for storage capacity in PCs.
With the new SD XC EX technology, which Samsung is now testing for its microSD cards, read speeds of up to 800 Mbps can be achieved. This is substantially higher than the current generation of (micro)SD cards that achieve read speeds of between 80 and 90 Mbps. With the faster UHS-II-compatible professional memory cards, a maximum of 250 Mbps can be reached.
In comparison, Samsung states that the SD XC EX standard ensures that the (micro)SD cards achieve about the same read speed as older SATA SSDs. This, therefore, makes the (micro)SD cards suitable, for example, for storage capacity in PCs or other devices that support the standard.
The SD XC EX standard allows SD cards to fully utilize a single lane of PCIe bandwidth. This should then provide theoretical speeds that exceed the UHS-1 standard “cap” of 104 Mbps or 312 Mbs for the UHS-II standard. There is also another UHS-III standard, but this standard almost never gets used.
Underutilized technology
SD XC EX technology has been around since 2018, but adoption is very low. Currently, only AData is said to provide (micro)SD cards with the technology with 256GB and 500GB of storage capacity. Lexar also announced (micro)SD cards with this technology but never made it to market.
According to experts, the adoption of this type of (micro)SD card would be low because there are quite a few technical challenges. To achieve the promised speeds, devices would have to support the SD XC EX standard. In addition, SD XC EX cards generate a lot of heat when they process large amounts of data. Within a (micro)SD card slot, there is no room to redirect this heat or apply cooling. Again, this would require SD XC EX cards to operate at slower speeds than intended.
Samsung card availability
Specifically, the South Korean tech giant is now testing a 256 GB version of an SD XC EX card. This should become available during the course of this year.
Also read: Samsung predicts a petabyte SSD in the next decade