Like its CF counterpart, this Crucial SD card is devoid of any on-card speed branding but a little dig around the companyâ€™s website reveals similar specs to its CF brethren. A minimum transfer rate of 3MB/s (20X) is stated and fortunately, it didnâ€™t suffer from the questionable write times we got for the Crucial CF card.
Indeed, it hovers around the 1MB/s mark when writing the 1.01GB of mixed files in multiple folders to the card â€“ about five times faster than Crucial CF card. However when reading the same data from the card, it was bottom of the pile when using the Crucial reader (3.5MB/s) and just above average in the SanDisk reader (6.8MB/s). That said these rates are quicker than the companyâ€™s CF card.
Change the data type to a 1.01GB folder of images and this SD card shows a marked improvement of 8.4MB/s when reading from the card and 4.3MB/s when writing to it. That read figure is up there with the best of the rest, but all the other SD cards manage to beat that write time. Unfortunately, it is also the slowest card in terms of both write and read speed when it was plugged into the Lexar SD reader. That said, Crucial isnâ€™t marketing this as a high-speed card and in the Lexar reader the read (9.2MB/s) and write (4.3MB/s) rate exceed the 3MB/s minimum transfer rate stated in Crucialâ€™s literature.
Similar to the Crucial CF card, it only manages 2.1MB/s in the 1D Mark II, so if in-camera write speed is important to you then itâ€™s probably best to go for one of the other SD cards.
The Crucial SD card is not pretending to be something it is not, and with it being the cheapest SD card here, it could make a good back-up if speed is not critical to you. A lifetime warranty is stated.