Memory Cards

2 articles

Tech 09 Sep 2026 7 min read

What the Speed Symbols on an SD Card Actually Mean

An SD or microSD card can carry several speed symbols at once: perhaps a 10 inside a broken circle, a 3 inside a U, and a mark such as V30. It is easy to assume that these numbers are competing estimates of the card’s maximum speed. They are not. Most of these marks are speed classes: standardized ways to state a minimum level of write performance under defined conditions. Different class systems were introduced for different generations and uses, so one card can legitimately qualify for several of them.

Storage SD Cards

Tech 03 Sep 2026 8 min read

How microSD Cards Expand Device Storage

A microSD card can add a surprising amount of storage to a small device. Phones, tablets, cameras, handheld game systems, dash cameras, and other electronics may use these tiny removable cards to hold photos, videos, downloads, maps, games, and other files. The basic idea is simple: a microSD card contains flash memory that keeps data even when power is removed. In practice, however, choosing and using one involves more than matching the physical shape. Capacity limits, file systems, speed ratings, workload requirements, and device support all affect whether a card will work well.

microSD Storage