Best Memory Cards Sony A7sIII

The Sony A7sIII has a very unique setup with dual UHS-II SD card slots that can also take the CFexpress Type A cards. But you might not need CFexpress cards. This guide will help you find the best memory cards for the Sony A7sIII and hopefully save you some money.

Sony A7sIII Memory Card Recommendations

You only need CFexpress type A cards if you record S&Q at fast frame rates.

UHS-II cards usually have two-speed classes associated with them, V90 and V60. 

V90 UHS-II cards offer a minimum bitrate of 90MB/s. The minimum requirement for 600Mbps ( 75MB/s ) H.264.

V60 UHS-II cards offer a minimum bitrate of 60MB/s. Minimum reqruiement 280Mbps ( 35MB/s ) H.265.

If you want to shoot S&Q with some higher frame rates, you’ll need CFexpress Type A cards. You can shoot with high frame rates like 120p in the different XAVC modes without the CFexpress Type A cards.

*In-Camera Speeds are from the Sony A9 II.

Also, see my Sony A7sIII List of Accessories.

Sony A7sIII Memory Card Compatibility

The Sony A7sIII has a very interesting setup. It allows for two different types of memory cards in the same slot (not at the same time).

The camera will take SD UHS-II cards or CFexpress Type A cards. 

What’s the difference between CFexpress Type A and SD Cards?

Quite a bit, but it mainly comes down to size and speed. CFexpress Type A cards are much faster and slightly smaller.

Do you need CFexpress Type A cards for the Sony A7sIII?

Only if you shoot S&Q at high frame rates.

What is the S & Q setting and why do you need it? 

S & Q stand for slow and quick. It creates a file that will be played back in slow motion set to your base frame rate. So the footage plays back in slow motion inside the camera.

When shooting S & Q you will need to use CFexpress Type A cards for XAVC S-I at high frame rates.

Sound will not be recorded in the S & Q mode.

We typically would not record in S&Q with Sony cameras but it looks like the new A7sIII might be doing something different here that requires a faster memory card.

The camera maxes as a bitrate of 280Mbps H.265 or 600Mbps H.264, so testing will need to be done. It is possible that Sony is giving us 280Mbps at 24p taken from a 120fps source, which would mean it is dumping 1400Mbps ( 175MB/s ) to 3000Mbps (  375MB/s ) to the card depending on the record mode. My guess is they use some other bitrate special to this mode.

This would produce a much nicer image if that is the case that users would likely want to take advantage of.

For now, the price of CFexpress Type-A cards is crazy high. You may want to forgo shooting S&Q 120p footage if not needed or use a smaller CFexpress Type A card just for when 120p S&Q recording is needed.

Sony A7sIII Memory Card Capacity

The Sony A7sIII can take any size memory card. If you want to use a 1TB memory card, the camera will take it. Keep in mind, if you use 32GB cards, you’ll only be able to format the card in a 32-bit filesystem, and you won’t be able to record clips larger than 4GBs.

Sony A7sIII Specs

To see how each UHS-II memory card performs in Sony cameras, here is a speed test from the Sony A9II.

Memory Card Speed Test | Fastest Memory Cards

These tests are taken with continuous burst high at ISO 100. The buffer is filled and the time it takes to clear the buffer is calculated against the record times.

Best Memory Cards For 4k Video

Sony A7sIII Video Specs & Recording Modes

There are a lot of different record modes with different Sony codecs.

What’s new to the Sony A7sIII is the XAVC HS and the XAVC S-I.

What’s the difference between XAVC HS, XAVC H-I, and XAVC S?

All three containers are capable of recording 10-bit 4:2:2. The main difference is H.265 vs H.264.

XAVC HS allows for H.265 recording.

XAVC S and S-I still only record to H.264. The S-I variant is an all intra recording. Meaning keyframes on every frame.

H.265 offers better compression performance at a lower bandwidth which makes it a much more efficient file. So H.265 can produce almost twice the quality at a similar file size as H.264 depending on the scenes.

The disadvantage of H.265 is it is harder on the CPU to decode and it will often require you to work with proxies when editing, which are actually very quick and easy to make.

H.264 is an older codec that was used by all the older Sony cameras. H.264 will support 10-bit at a 4:2:2 subsampling but it’s not as efficient as H.265. You can still get great quality out of H.264 since Sony increased the bitrate to 600Mbps with H.264.

This will give you similar quality to H.265. Most computers will be able to edit these files without any issues, so you’ll have to test for yourself the advantages and disadvantages of each system. I personally just edit with H.265, using the proxies in Premiere.

Record Limit: Unlimited
Audio FIle Format: AAC, Linear PCM

Should You Use XAVS HS or XAVS S-I?

You should use XAVC HS with the H.265 recording when you can. It is a better codec and then you should develop a proxy post-production workflow in Premiere to speed up the editing process. It’s incredibly simple to do once you’ve got it all set up. It’s worth the file size advantage and image quality advantage.

I have a guide to proxy editing here

If you need to get to editing quickly without proxies, you’ll likely want to shoot with XAVC S-I which records H.264. Keep in mind the file sizes will be much larger if you’re using the max quality of 600Mbps and you’ll need to use more expensive V90 cards.

What Size Memory Card Is Best?

The size of the memory cards you’ll need really depends on record settings and the type of video you’re shooting. You’ll probably want to start with a 128GB card which gives you 61 minutes when recording with the 280Mbps H.265 bitrates. This is going to be enough for short videos that take a few hours to shoot. 

If you shoot 600Mbps with H.264 because you don’t want to deal with the additional post-processing labor involved with H.265, then you may want to start with a 256GB card.

On long shoot days or big projects, you may either want to go with a bigger card or clear off the cards midday, which means you have to bring some sort of computer and backup drives. So this all depends on your budget and workflow.

Sony A7sIII Record Times – Memory Card Capacity

Here are the record times for 4k bitrates based on a few memory card sizes.

Use this table to see the memory card capacity with different record settings.

Avoiding Counterfeit Memory Cards

Counterfeit memory cards still plague many online retailers and you can end up with them if you’re not careful.

To avoid counterfeit cards there are a few precautions you can take.

First, buy from trusted stores only. BHphoto, Adorama, etc. If you buy from Ebay, or Amazon, make sure that you still select a trusted seller. Even then occasionally you can get mixed inventory. I haven’t had it happen when buying from Amazon personally, but I’ve heard about it happening in Europe. Most of the time these counterfeit cards look too good to be true, or they are extremely popular cards. 

How to test for counterfeit memory cards?

Counterfeit memory cards are often made by hacking the memory card controller to report a false capacity. For example, they’ll take a 32GB card, and hack it to read as though it’s a 128GB card.

Everything will work fine for days or weeks until you cross that 32GB threshold, then the card fails.

What you can do with the Sony A7sIII is set the camera to record video at 600Mbps, and let it run on each card you buy until it fills the card. If the card reaches rated capacity then it’s most likely authentic. 

Best Memory Cards Sony A7sIII Conclusions

Shopping for memory cards for the Sony A7sIII is a little tricky since it takes two different types of cards. When CFexpress Type A cards come down in price it would make sense to just buy two of those and you’ll have a system that can handle any record mode.

If you’re just shooting fairly casually and you don’t need that S&Q record mode and you’re fine with capturing 120p the normal way, then any UHS-II card will work fine.

The big takeaway would be to remember

UHD 4k H.265 XAVC HS, v60 UHS-II cards are fine.

UHD 4k H.264 XAVC S-I, you will need v90 UHS-II cards.