V30 vs V60 vs V90 SD cards: which do you need?

What V30, V60 and V90 guarantee

The Video Speed Class mark states a minimum sustained write speed in megabytes per second: V30 guarantees at least 30 MB/s, V60 at least 60 MB/s and V90 at least 90 MB/s. This is more useful for video than the much larger peak speed printed on the packaging, because a camera must keep writing for the entire clip.

Camera bitrates are normally quoted in megabits per second. Divide by eight to compare them with a card rating in megabytes per second: 200 Mb/s is 25 MB/s, while 600 Mb/s is 75 MB/s. Leave margin and follow the camera maker’s approved-card list because recording modes may impose interface, capacity or formatting requirements beyond the simple calculation.

When paying for V90 makes sense

V30 is sufficient for many compressed 4K modes, while high-bitrate intraframe recording, some 4K high-frame-rate modes and demanding burst photography can require V60 or V90. A faster card does not improve image quality; it only enables modes and clearing speeds that the camera can actually use.

Check whether the camera supports UHS-II before paying its premium. UHS-II cards have a second row of contacts and can also speed up transfers through a compatible reader, but a UHS-I camera cannot take advantage of the faster bus.

Choose capacity after speed

Once the speed requirement is satisfied, use bitrate and expected shoot length to choose capacity. Two smaller cards can limit the amount lost to a single failure, while one large card reduces interruptions. For important work, buy from a reputable retailer, test the full recording mode before the shoot and carry a known-good spare.

• Find the maximum bitrate of the exact mode you intend to use.
• Divide Mb/s by eight, then select a comfortably higher sustained rating.
• Confirm the card type and capacity in the camera manual.
• Use Apertally’s storage calculator to estimate realistic recording time.