A memory card speed comparison between many of the popular SD memory cards in the Sony A7r, A7s and A7.
Use this guide to find the best memory cards for video or your style of shooting.
Best Memory Cards For The Sony A7r, A7s
To determine the best SD memory card for the Sony A7 series cameras, I created a memory card speed test where I shoot three rounds of RAW bursts on speed priority for a designated time. I then record the total amount of data from each round and the time it took to clear the camera’s memory buffer. The results are calculated and averaged.
You can also check the best memory cards for the following E-Mount cameras for an updated list of cards:
SD Memory Card Speed Tests For The Sony A7r
The first read and write speeds listed are done as a control with the Macbook Pro SD USB 3.0 card reader. Next are the write speed results taken from the Sony A7r.
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|SD Memory Cards||USB 3.0 Read||USB 3.0 Write||Sony A7r Write||Order|
|Kingston 64GB SDXC Class 10 / U3||88.1 MB/s||74.3 MB/s||35.46 MB/s||Amazon|
|Sandisk Extreme Plus 64GB SDXC Class 10 / U3||88.9 MB/s||62.0 MB/s||35.10 MB/s||Amazon|
|Sandisk Extreme 64GB SDXC Class 10 U/3||71.3 MB/s||52.1 MB/s||34.90 MB/s||Amazon|
|Sandisk Extreme Pro 64GB SDXC Class 10 / U3||89.0 MB/s||84.7 MB/s||34.86 MB/s||Amazon|
|Transcend 64GB SDXC Class 10 / U3||87.7 MB/s||64.1 MB/s||34.23 MB/s||Amazon|
|PNY 64GB SDXC Class 10 / U1||86.1 MB/s||54.5 MB/s||34.10 MB/s||Amazon|
|Samsung Pro 64GB SDXC Class 10 / U1||86.8 MB/s||77.2 MB/s||34.00 MB/s||Amazon|
|Lexar 600x 64GB SDXC Class 10 / U1||85.6 MB/s||60.1 MB/s||33.53 MB/s||Amazon|
|Sony 64GB SDXC Class 10 / U3||87.2 MB/s||71.9 MB/s||33.46 MB/s||Amazon|
All the memory cards tested gave very similar results. This sometimes means there is a bottleneck happening and my guess would be the processor. Because of this bottleneck, all cards listed here will basically give you the same level of performance.
When shooting JPEG only performance drops to about 20MB/s on the Sony A7r. Likely because JPEG puts more load on the processor.
All the Sony mirrorless cameras give very similar results to the A7r. There just seems to be that bottleneck that slows every card to around 33-34MB/s no matter what camera or card I test. I’ve tested the A7s which I’ll post soon. Still working on getting my grubby little hands on the Sony A7ii, but I imagine it will give similar results.
Best UHS-I SD Memory Cards
Based on my experience with using memory cards in Sony cameras these are the only cards I recommend. There are a few other Sony cards that work well also.
Best Memory Card For The Sony A7s, A7ii Video Modes
The Sony A7s and A7ii shoot on an internal format of XAVC, which gives you 50mb/s. Which will give you something around 6-7MegaBytes a second.
Recording in XAVC requires a SDXC card which means 64GB or larger. A smaller 32GB card or SDHC will not work when trying to record to XAVC.
Everything You Could Ever Want To Know About Memory Cards
Since 90% of the people access this page just want to know exactly what cards will work, I’ve listed them above. But if you’re a technophile like me and want to learn almost everything there is to know about SD cards and how to choose them for your camera, then you’ll enjoy this read!
There are really three things you should know right now when buying SD cards.
1. You don’t need UHS-II cards for 90% of the cameras out there. Buying one will just be a waste of money unless you really want faster transfer speeds from your UHS-II card to your computer. If your computer or card reader even supports it.
2. You should be buying SDXC memory cards now. They are usually 64GB and bigger. The reason? Many video codecs require it. Especially Sony cameras.
3. The little U with the number in it. You’ll see 1 or 3. Meaning, class 1, or class 3. This stands for the minimum write speed. Class 1 has a minimum write speed of 10MB/s, Class 3 has a minimum write speed of 30MB/s. This doesn’t mean a Class 1 card can’t write 30MB/s. It just means when the card is near full or fragmented, it will still be able to write at its minimum speed.
The speeds listed on the cards are referring to read speeds which don’t really do you any good when taking pictures.
Shooting Stills A7II, A7r, A7s
Shooting Photography and Video on the Sony A7 and A7r will require a Memory Stick PRO Duo, PRO-HG Duo, XC-HG Duo, SD, SDXC and SDHC class memory cards. Basically almost any SD card can work. Just not the tiny one. Although the tiny one will work with an adapter.
All these cameras use the UHS-I Bus Speed Interface which will max at 104MB/s.
When shopping for the Best SD Card for my A7r my first concerns were “are my SD cards I currently own going to be fast enough for the A7r’s massive data output?” After doing a bit of research, my answer was, yes. Here is why.
Sony A7r Speeds
The Sony A7r shoots a 36.3 MP file, which delivers RAW images roughly 37-38 Megabytes in size.
Burst Speeds: 4 fps, 1.4 after buffer.
37MB x 4fps = 148MB/s.
Sony A7r Buffer
The buffer on my camera seems to fill up after 16-18 shots. Which means the buffer is about a half a gig large. And when the buffer is full it shoots at 1.4 fps.
Then depending on the speed of your card it will take somewhere between 15-25 seconds to clear the buffer and write the data to the card.
So if you’re doing a lot of burst continuous shooting with the A7r, get a faster card.
Sony A7 Speeds
The Sony A7 shoots a 24.3MP file which delivers RAW files roughly around 25MB.
Burst Speeds: 5 fps, 1.5 after buffer.
25MB / 5fps = 125MB/s.
Sony A7 Buffering
The camera has a buffer that will allow you to shoot 49 Jpeg shots, or 21 Raw.
The length of time to clear your buffer and write to the card depends on the speed of your card.
*On any of these cameras buying a card faster than 104MB/s is a complete waste of money since the interface bottlenecks at UHS-I speeds. And you will only see the benefits of a faster card when it comes to clearing your buffer after long continuous bursts shots. So is spending an extra $50 bucks on a faster card worth saving you 10 seconds every time you shoot a burst of 21 shots?
Card Speed Numbers Ratings
Keep in mind, when a card is rated at 96MB/s, that only means it has a max burst speed of 96MB/s. Rarely will a card consistently perform at that number.
There is something called minimum write speed that’s actually a more important number to pay attention to which isn’t often listed on the card. We’ll go over that in a bit.
What About Video, Won’t I Need A Faster Card?
Shooting video is like shooting a stream of JPEG’s. JPEG’s only use a fraction of the data rate of a RAW image. You’ll only need a fraction of the speed.
Currently the Sony A7ii, A7r and A7s can all shoot 1080p60 using the AVCHD codec. The AVCHD codec bottlenecks at 24Mb/s, topping out at 28Mb/s when shooting 60fps. That’s a data rate of around 3.5MB/s.
Any card with a reasonable speed should work for recording in AVCHD.
Memory Card Speed Class Ratings
If you can’t find a data rate listed on your card there is another way of knowing how fast it is. Each card has a number code on it. The older Speed Class cards have four numbers. Class 10, 6, 4 and 2. Newer UHS-I cards have Class 1, 3. You also might see a I or a II, depending if it’s UHS – I or UHS – II. Or even a U1 and U3.
For ‘Speed Class’ the Hierarchy goes like this.
10 – High Speed Bus – Full HD video recording – 10MB/s Minimum write speed
6 – Normal Bus – Full HD video recording – 6MB/s Minimum write speed
4 – Normal Bus – Somewhere between HD and SD Video Recording – 4MB/s Minimum write speed
2 – Normal Bus – SD video recording – 2MB/s Minimum write speed
U1 / V10 – UHS – Full higher potential recording, real-time broadcast, large HD files – 10MB/s minimum write speed.
U3 / V30 – UHS – Capable of recording full 4k or 2k video – 30MB/s minimum write speed.
About Minimum Speeds
The Minimum speeds listed above have to do with card fragmentation. When a drives information gets scrambled around or when a drive gets near full, speeds will usually be reduced.
Having a minimum speed of 10MB/s or 30MB/s guarantees that no matter how fragmented a SD card gets, you’ll still get at least those numbers. It’s important for video, not so much for photography since you’re working with a buffer.
The Sony A7r is compliant up to UHS-I. When using a UHS-I card that’s been fragmented and near full, you’ll still be rated at 10MB/s, which is more than enough for video, but you might end up having to do a little buffering on a long burst.
The Best SD memory card for video using the Sony A7ii, A7r, A7s will be a Class 6, Class 10 or USH – I. A Class 4 card would be riding the line of acceptable speeds for video.
UHS-II cards have a different pin configuration and may not work with the Sony A7 or A7r.