Choosing the Right Memory Card for Your Sony a6700

Quick recommendations

If you just want some solid recommendations on which memory card to get for your Sony a6700, here you go. Any of these SD cards will work well in the a6700.

These SD cards are fast enough to unlock all of the a6700’s video features, including the high-bitrate 4K120 and All-Intra modes. They have a strong track record of reliability in my testing and are readily available.

Sony a6700 memory card requirements & compatibility

For our purposes here, I’m focusing on memory cards that will let you use all of the Sony a6700’s features. It doesn’t make much sense to me to get a memory card that will only let you use some of the a6700’s capabilities.

The Sony a6700 is a 26-megapixel APS-C mirrorless camera that punches well above its weight class. It shoots video up to 4K120 and photos at up to 11 frames per second. Those features place significant demands on the memory card.

If you just want the short version: the a6700 has a single UHS-II SD card slot, and any V90-rated UHS-II SDXC card will let you use every feature the camera has, including 600 Mbps All-Intra video. If you don’t shoot All-Intra, a V60 UHS-II SDXC card covers everything else, including 4K120, for less money.

Where things get critical is that the a6700 can record video at exceptionally high bitrates — up to 600 Mbps in the XAVC S-I (All-Intra) 4K mode. Even standard 4K120 recording clocks in at 280 Mbps.

If you insert a standard card (like a V30 or slower), the camera will simply gray out these high-end recording options in the menu, preventing you from using them entirely.

The warning you get with a card that’s too slow

If you try to select a high-quality video mode with a slow card, you will see a warning message like this, telling you to use a memory card higher than V60 or V90:

General recommendations

1. Use an SD card with a V90 rating for total compatibility

The V90 rating guarantees a minimum sustained write speed of 90MB/s. This is the only class of card that officially supports the a6700’s XAVC S-I 4K (All-Intra) mode at 600 Mbps. If you plan to shoot in this codec for easier editing, you must have a V90 card.

Don’t go by the big number printed on the front of the card. Those figures are almost always read speeds — how fast the card hands data to your computer — and they say nothing about how fast the card can keep writing while the camera fills it. The V rating is the one the camera cares about, because it’s a guaranteed minimum sustained write speed: V60 means at least 60MB/s, V90 at least 90MB/s. A card advertised at 300MB/s that is only rated V30 will still gray out the a6700’s high-bitrate modes.

However, if you are happy sticking to the compressed codecs (XAVC S and XAVC HS), which top out at roughly 280 Mbps, a high-quality V60 card is perfectly sufficient and much cheaper.

There is one exception worth knowing about before you settle on V60. Sony’s own memory card chart for the a6700 calls for a V90 card when you shoot S&Q slow motion at 120fps (or 100fps) with the record frame rate set to 24p, 25p, or 30p. The finished clip plays back slowed down, but the camera is still writing every one of those 120 frames a second while it records, so the data rate is higher than the plain 4K120 movie mode. Regular 4K120 movie recording, without S&Q, is fine on a V60 card.

2. Use UHS-II

The a6700 has a single UHS-II SD card slot.

This single slot does not support CFexpress Type A cards, unlike some of Sony’s full-frame bodies (the a7R V and a1, for example). If you’re coming from one of those cameras, don’t buy CFexpress media for the a6700 — it simply won’t fit.

The slot itself has moved on this generation. On the a6700 it sits behind its own door on the left side of the body, not in the battery compartment underneath as it was on the a6600 and the a6000-series bodies before it. That means you can swap cards with the camera still on a tripod plate.

Unlike older models that had UHS-I slots, the a6700 takes full advantage of the extra pins on UHS-II cards. Using a UHS-II card not only enables high-end video modes but also drastically reduces the time the camera spends “writing” to the card after a burst of photos.

3. Stick with SDXC

I strongly recommend sticking with SDXC (64GB and larger) cards.

The a6700’s high-end video codecs (XAVC S-I and XAVC HS) require the exFAT file system, which is only found on SDXC cards. If you use an older SDHC card (32GB or smaller), many of the camera’s video settings will be unavailable.

Sony a6700 SD card detailed recommendations

So which SD card should you get for your Sony a6700? The instruction manual gives the technical data, but here is the practical breakdown based on my independent SD speed tests.

Do you really need a good memory card?

A better memory card allows you to use all of the a6700’s features without hitting a wall. A card that isn’t fast enough can cause the camera to lock up while saving photos, drop frames during video recording, or overheat as it struggles to write data.

However, you don’t need to overspend. If you never shoot 4K video or massive bursts, a mid-range V60 card offers the perfect balance of performance and price.

How to format SD cards

Always format your memory card inside the a6700. This creates the specific folder structure and database files the camera needs to operate correctly.

How to format SD cards in the Sony a6700

On the Sony a6700, you can find the format function under:

MENU > Shooting > Media > Format

I have a more detailed post on how to format the SD card in a Sony a6700 that walks through the specific menu steps.