If you like to tinker with single-board computers, then you probably have a bunch of Raspberry Pi (or equivalent) boards all needing a microSD card to boot from. Often, for simple projects, the card doesn’t have to be anything too special – as long as it’s reasonably fast and large enough, it will do. As I haven’t purchased any new microSD style cards in a while, I was running low with a few of my older boards sitting around with no card to use.
Having resisted the urge to pick up a few cards, I saw an online bargain posting for a three-pack of Strontium Nitro 16Gb microSDHC cards with adapter for AU$10.80 including shipping which I couldn’t turn down. At that price (assuming the adapter cost nothing), I was paying AU$3.60 for each 16Gb card, or about 22.5c/Gb. That’s not the cheapest flash memory has gone for – recently we’ve seen SSDs at the 1Tb mark drop to 19.9c/Gb, but the overhead of getting several cards also increases costs slightly.
The product comes packaged in a retail hanging card, in the standard Strontium yellow-red-white colour scheme. The package claims 433X speed, up to 65MB/s (read) speeds with lower write speeds. The items are packed within a clear plastic bubble, which can be seen from the outside. The cards are labelled “horizontally” in a striped-colour design which bears some similarity to Sandisk and Samsung offerings. The packet has the Australian RCM mark on the rear, indicating locally approved stock, with a product number of SRN16GTFU13C1A and claims to be Made in Taiwan. The packet is perforated for easy opening, although I didn’t find this to be effective.
The plastic tray can be removed from the cardboard.
The adapter is very plain, but functional, only having the brand printing on the front and no specifics on the rear.
The cards all contain the same etching on the rear, which claims to be Made in Taiwan.
The card is pre-formatted with a volume label of STRONTIUM with 15,632,171,008 bytes total capacity (14.5GiB).
Further analysis shows that the card is partitioned with an MBR, containing a partition that starts at sector 8192 (4kiB) into the card.
The relevant card identification is as follows:
CID: 8454464d53000000202c5d002a01181 CSD: 400e00325b59000074877f800a400091
Unfortunately, due to the change in my system, my benchmarking system is no longer consistent with the old SD card database. Instead, tests are being performed using the Transcend RDF8 USB 3.0 reader connected to my new workstation. Testing was performed with the card in its factory format.
On a fresh, unwritten card, the read speeds averaged 91.2MB/s. However, once fully written, the true sequential read performance is revealed to be about 68.5MB/s which is slightly above the package claim of 65MB/s.
Writing to the card achieved an average rate of 10.8MB/s, barely reaching the Class 10 requirement.
Random access I/O figures showed relatively consistent read service times, but write service times did occasionally encounter longer delays of up to 351ms.
CrystalDiskMark seemed somewhat more complimentary about the card’s performance, with sequential reads scoring 80.42MB/s and writes at 11.90MB/s. Small block 4k accesses do take a significant hit – around 3.6MB/s read and 0.6MB/s write. This level of performance is quite unremarkable.
The ATTO benchmark shows the card reaching full I/O performance by 64KB, which is not a bad result, suggesting potentially smaller flash page sizes. Smaller accesses do suffer significant penalties, as is normally the case with flash memory. The write speeds peaked at 11.7MB/s, with read speeds peaking about 76.9MB/s.
H2testw results are relatively consistent with the previous, indicating write speeds just compliant with Class 10 requirements and read speeds of 73.6MB/s which exceed the claimed 65MB/s. No data integrity problems were encountered operating with the default format.
The Strontium Nitro 16Gb Class 10 UHS-I MicroSDHC cards aren’t anything special, which is exactly what I expected given the price. The write speeds barely meet the Class 10 standard, with the read speed being quite close to (or even above, depending on the benchmark) the 65MB/s advertised, so it is an honest offering. Unfortunately, when compared with some of the other Class 10 competition which can push write speeds up to 20MB/s or even higher with read speeds closing in on 90MB/s, these cards do feel a little slow by comparison. For the price, it was still worthwhile.