SanDisk Extreme Pro V30 A2 microSDXC UHS-I U3 64 GB (SDSQXCY-064G-GN6MA)

Record speed

Extreme Pro is claimed to comply with C10 General Speed Class, U3 UHS Speed Class, and V30 Video Speed Class. Separately, it is announced that the card meets the requirements of class A2 for working with mobile applications, games, etc. The Extreme Pro description also mentions that this card, along with a linear read speed of 170 MB / s, can offer a linear write speed reaching up to 90 Mbps. As you can see, the prefix Pro in the name is not just there, on paper it is one of the fastest microSD cards.

Expectations and reality

However, such claims by SanDisk need to be verified (from experience). During practical measurement, it turned out that it does not fully correspond to the claimed characteristics. We couldn't get a linear write speed of 170 Mbps. The real figure turned out to be slightly below 100 MB / s, synthetic tests painted a similar picture. And the point here is a little trick, which is mentioned in a small footnote on the company's website: "To get this result, you need a device of the appropriate class." For example, a branded card reader, which you can still find. It turns out the story is like with SSD on the fourth generation PCI-E bus: the speeds are crazy, but there are very few equipment on the market that is ready to support such a speed.

Great for smartphones

Extreme Pro did not impress with performance in small-block operations either: when writing, performance indicators turned out to be only slightly higher than the requirements determined by the speed class A1. In other words, the characteristics given in the Extreme Pro specification slightly embellish its capabilities. While not as impressive in real life as it is on paper, it's still one of the fastest microSD cards on the market. Given the full protection against any adversity and the price, which is much lower than the price tag at the start, we get quite an interesting option for a variety of tasks, whether it is a backup storage in a smartphone or the main memory for an action camera.