One of the great things about SD cards is their speed class rating. As long as it says V30, as with the Lexar Professional SILVER SDXC UHS-I 256GB card, you know that the minimum write speed is going to be 30 MB per second. In real terms, this means that alongside your camera’s buffer, the card should be more than capable of storing multiple files easily.
For example, if we take the Sony A7 IV, with its JPEG files of around 10 MB and RAW files of around 70 MB each, that’s a combined file size of about 80 MB. While 30 MB per second might not sound like a great deal when compared to those large file sizes, in reality, when coupled with the buffer and the actual write speed of the SD card, it should be more than enough to handle general shooting, even in high-speed burst mode.
In real-world terms, this means that if you’re in burst mode on the A7 IV, you can store about 17 combined JPEG and RAW files before the camera starts to slow down. This compares with around 20 combined JPEG and RAW files with a higher-end UHS-II card and an almost unlimited amount when using a CFexpress Type A card.
So, in comparative real-world tests, while there is an increase in performance when you pay extra for a UHS-II card like the Lexar Professional SILVER PRO, the difference when shooting images isn’t that significant. You can save a considerable amount of money by opting for the UHS-I version over the UHS-II version.
In the real-world tests, this card delivered a strong performance. However, if you are shooting sports and wildlife and have a camera capable of higher speeds, upgrading to a UHS-II card for that small amount of additional speed or opting for a CFexpress Type A or Type B card, depending on your camera manufacturer, can be a definite advantage. However, considering the additional cost of those types, this UHS-I card offers pretty decent performance.
The results of this performance are reflected in benchmark tests, which show that the card meets and exceeds both read and write performance expectations, proving that the transfer rates this card is capable of are truly impressive.
Benchmark Results
AJA System Test Light: Read: 198 MB/s, Write: 185 MB/s
CrystalDiskMark: Read: 207.14 MB/s, Write: 184.74 MB/s
AS SSD: Read: 186.19 MB/s, Write: 173.17 MB/s
ATTO: Read: 184.17 MB/s, Write: 176.19 MB/s