In this guide I test the only four CFexpress Type-A cards on the market today in my Sony A1 to find out which CFexpress cards clear the A1’s buffer the fastest.
Please note that the Sony A1 supports CFexpress Type-A cards, the physically larger Type-B cards are not supported.
If you are curious about how quickly UHS-II memory cards clear the buffer, then please visit my complete Sony A1 Memory Card Guide where I’ve tested 10 different UHS-II cards in-camera.
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Sony A1 Forum & Facebook Group
If you are looking for further help and advice on the a1 or would simply like to share your photos and videos, then please head over to our new Sony A1 Forum. If you prefer Facebook then I also run the Sony A1 Shooters Group.
Quick CFexpress Card Speed Comparison
If you don’t want to dive into my buffer tests a little further down then here’s a quick speed comparison of the CFexpress Type-A cards available today.
All tests were done using my Sony A1 with 160GB capacity cards.
| Memory Card | In-Camera Write Speed | Check Price & Reviews |
|---|---|---|
| 1. Delkin Devices BLACK CFexpress Type-A | 617 MB/s | B&H Photo | Amazon |
| 2. Delkin Devices POWER CFexpress Type-A | 617 MB/s | B&H Photo | Amazon |
| 3. Sony CEA-G CFexpress Type-A | 600 MB/s | B&H Photo | Amazon |
| 4. ProGrade Digital CFexpress Type-A Cobalt | 600 MB/s | B&H Photo | Amazon |
CFexpress Card Buffer Tests
Here I test how many shots you can take in each file format and drive mode before hitting the A1’s buffer.
All of these tests have been carried out with the A1 in full manual mode.
1. Delkin Devices BLACK CFexpress Type A
The Delkin Devices BLACK CFexpress Type-A memory cards are designed and supported in the USA.
These BLACK cards also include a 48 Hour Replacement Guarantee.
They are available in both 80GB and 160GB capacities. Both capacities have the same read speeds but the larger 160GB card has a slightly faster write speed.
- Max Read Speed: 880MB/s
- Max Write Speed: 730MB/s (80GB)
- Max Write Speed: 790MB/s (160GB)
In-Camera Speed & Buffer Test Results
When shooting uncompressed raw to slot 1 in manual mode/focus with a shutter speed of 1/250th the in-camera write speed is around 617 MB/s.
Here are my in-camera speed test results using a 160GB card:
Drive Mode Hi+ (Max 30fps)
Please note that the maximum speed of 30 fps is only possible in compressed RAW, JPEG and HEIF file formats.
| Image Type | Shots Before Hitting Buffer | Time to Clear Buffer (Seconds) |
|---|---|---|
| Uncompressed RAW (108.3MB) – 20 fps | 89 | 11.05 |
| Compressed RAW (54.2MB) – 30 fps | 155 | 9.61 |
| Lossless Compressed RAW (59.5MB) – 20 fps | 106 | 6.51 |
| JPEG Extra Fine (26MB) – 30 fps | 128 | 7.46 |
| Uncompressed RAW (108.3MB) + JPEG Extra Fine (26MB) – 20 fps | 76 | 14.46 |
| Compressed RAW (54.2MB) + JPEG Extra Fine (26MB) – 30 fps | 119 | 15.00 |
| Lossless Compressed RAW (59.5MB) + JPEG Extra Fine (26MB) – 20 fps | 75 | 9.61 |
| HEIF (4:2:0) Extra Fine (15.7 MB) – 30 fps | 159 | 5.95 |
| HEIF (4:2:2) Extra Fine (18 MB) – 30 fps | 151 | 6.83 |
Drive Mode Hi (Max 20fps)
| Image Type | Shots Before Hitting Buffer | Time to Clear Buffer (Seconds) |
|---|---|---|
| Uncompressed RAW (108.3MB) | 89 | 11.05 |
| Compressed RAW (54.2MB) | 265 | 11.35 |
| Lossless Compressed RAW (59.5MB) | 106 | 6.51 |
| JPEG Extra Fine (26MB) | 179 | 7.43 |
| Uncompressed RAW (108.3MB) + JPEG Extra Fine (26MB) | 76 | 14.46 |
| Compressed RAW (54.2MB) + JPEG Extra Fine (26MB) | 144 | 15.83 |
| Lossless Compressed RAW (59.5MB) + JPEG Extra Fine (26MB) | 75 | 9.61 |
| HEIF (4:2:0) Extra Fine (15.7 MB) | 284 | 5.88 |
| HEIF (4:2:2) Extra Fine (18 MB) | 267 | 6.75 |
Drive Mode Mid (Max 15fps)
| Image Type | Shots Before Hitting Buffer | Time to Clear Buffer (Seconds) |
|---|---|---|
| Uncompressed RAW (108.3MB) | 103 | 11.35 |
| Compressed RAW (54.2MB) | 441 | 11.70 |
| Lossless Compressed RAW (59.5MB) | 174 | 6.73 |
| JPEG Extra Fine (26MB) | 372 | 7.25 |
| Uncompressed RAW (108.3MB) + JPEG Extra Fine (26MB) | 83 | 14.23 |
| Compressed RAW (54.2MB) + JPEG Extra Fine (26MB) | 179 | 15.18 |
| Lossless Compressed RAW (59.5MB) + JPEG Extra Fine (26MB) | 99 | 10.11 |
| HEIF (4:2:0) Extra Fine (15.7 MB) | Never hits buffer | < 2.00 |
| HEIF (4:2:2) Extra Fine (18 MB) | Never hits buffer | < 2.00 |
Price Check & Buyer Reviews for Delkin Devices BLACK CFexpress Type A
At: Amazon | B&H Photo
2. Delkin Devices POWER CFexpress Type A
The Delkin Devices POWER CFexpress Type-A memory cards are designed and supported in the USA.
They are available in both 80GB and 160GB capacities, both capacities have the same read speeds but the larger 160GB card has a slightly faster write speed.
- Max Read Speed: 880MB/s
- Max Write Speed: 730MB/s (80GB)
- Max Write Speed: 790MB/s (160GB)
In-Camera Speed & Buffer Test Results
When shooting uncompressed raw to slot 1 in manual mode/focus with a shutter speed of 1/250th the in-camera write speed is around 617 MB/s.
Here are my in-camera speed test results using a 160GB card:
Drive Mode Hi+ (Max 30fps)
Please note that the maximum speed of 30 fps is only possible in compressed RAW, JPEG and HEIF file formats.
| Image Type | Shots Before Hitting Buffer | Time to Clear Buffer (Seconds) |
|---|---|---|
| Uncompressed RAW (108.3MB) – 20 fps | 89 | 11.04 |
| Compressed RAW (54.2MB) – 30 fps | 155 | 9.63 |
| Lossless Compressed RAW (59.5MB) – 20 fps | 106 | 6.52 |
| JPEG Extra Fine (26MB) – 30 fps | 128 | 7.45 |
| Uncompressed RAW (108.3MB) + JPEG Extra Fine (26MB) – 20 fps | 76 | 14.48 |
| Compressed RAW (54.2MB) + JPEG Extra Fine (26MB) – 30 fps | 119 | 15.02 |
| Lossless Compressed RAW (59.5MB) + JPEG Extra Fine (26MB) – 20 fps | 75 | 9.65 |
| HEIF (4:2:0) Extra Fine (15.7 MB) – 30 fps | 159 | 5.96 |
| HEIF (4:2:2) Extra Fine (18 MB) – 30 fps | 151 | 6.82 |
Drive Mode Hi (Max 20fps)
| Image Type | Shots Before Hitting Buffer | Time to Clear Buffer (Seconds) |
|---|---|---|
| Uncompressed RAW (108.3MB) | 89 | 11.04 |
| Compressed RAW (54.2MB) | 265 | 11.37 |
| Lossless Compressed RAW (59.5MB) | 106 | 6.52 |
| JPEG Extra Fine (26MB) | 179 | 7.43 |
| Uncompressed RAW (108.3MB) + JPEG Extra Fine (26MB) | 76 | 14.48 |
| Compressed RAW (54.2MB) + JPEG Extra Fine (26MB) | 144 | 15.83 |
| Lossless Compressed RAW (59.5MB) + JPEG Extra Fine (26MB) | 75 | 9.65 |
| HEIF (4:2:0) Extra Fine (15.7 MB) | 284 | 5.89 |
| HEIF (4:2:2) Extra Fine (18 MB) | 267 | 6.75 |
Drive Mode Mid (Max 15fps)
| Image Type | Shots Before Hitting Buffer | Time to Clear Buffer (Seconds) |
|---|---|---|
| Uncompressed RAW (108.3MB) | 103 | 11.34 |
| Compressed RAW (54.2MB) | 441 | 11.71 |
| Lossless Compressed RAW (59.5MB) | 174 | 6.76 |
| JPEG Extra Fine (26MB) | 372 | 7.28 |
| Uncompressed RAW (108.3MB) + JPEG Extra Fine (26MB) | 83 | 14.22 |
| Compressed RAW (54.2MB) + JPEG Extra Fine (26MB) | 179 | 15.21 |
| Lossless Compressed RAW (59.5MB) + JPEG Extra Fine (26MB) | 99 | 10.12 |
| HEIF (4:2:0) Extra Fine (15.7 MB) | Never hits buffer | < 2.00 |
| HEIF (4:2:2) Extra Fine (18 MB) | Never hits buffer | < 2.00 |
3. Sony CEA-G CFexpress Type-A
Sony CEA-G Series CFexpress Type-A memory cards can write up to 700MB/s and read up to 800MB/s according to Sony and they are available in 80GB and 160GB capacities.
This Tough version has been rigidity tested to 150 newtons to protect your card data during drops from up to 7.5 meters, they are also IP57 rated for dust and moisture protection.
In-Camera Speed & Buffer Test Results
When shooting uncompressed raw to slot 1 in manual mode/focus with a shutter speed of 1/250th the in-camera write speed of this card is around 600 MB/s.
Here are my in-camera speed test results using a 160GB card:
Drive Mode Hi+ (Max 30fps)
Please note that the maximum speed of 30 fps is only possible in compressed RAW, JPEG and HEIF file formats.
| Image Type | Shots Before Hitting Buffer | Time to Clear Buffer (Seconds) |
|---|---|---|
| Uncompressed RAW (108.3MB) – 20 fps | 87 | 11.45 |
| Compressed RAW (54.2MB) – 30 fps | 152 | 9.80 |
| Lossless Compressed RAW (59.5MB) – 20 fps | 105 | 6.11 |
| JPEG Extra Fine (26MB) – 30 fps | 133 | 7.05 |
| Uncompressed RAW (108.3MB) + JPEG Extra Fine (26MB) – 20 fps | 75 | 14.26 |
| Compressed RAW (54.2MB) + JPEG Extra Fine (26MB) – 30 fps | 125 | 15.10 |
| Lossless Compressed RAW (59.5MB) + JPEG Extra Fine (26MB) – 20 fps | 85 | 9.75 |
| HEIF (4:2:0) Extra Fine (15.7 MB) – 30 fps | 161 | 5.61 |
| HEIF (4:2:2) Extra Fine (18 MB) – 30 fps | 161 | 5.61 |
Drive Mode Hi (Max 20fps)
| Image Type | Shots Before Hitting Buffer | Time to Clear Buffer (Seconds) |
|---|---|---|
| Uncompressed RAW (108.3MB) | 87 | 11.45 |
| Compressed RAW (54.2MB) | 265 | 11.45 |
| Lossless Compressed RAW (59.5MB) | 105 | 6.11 |
| JPEG Extra Fine (26MB) | 210 | 6.93 |
| Uncompressed RAW (108.3MB) + JPEG Extra Fine (26MB) | 75 | 14.26 |
| Compressed RAW (54.2MB) + JPEG Extra Fine (26MB) | 146 | 14.96 |
| Lossless Compressed RAW (59.5MB) + JPEG Extra Fine (26MB) | 85 | 9.75 |
| HEIF (4:2:0) Extra Fine (15.7 MB) | 299 | 6.25 |
| HEIF (4:2:2) Extra Fine (18 MB) | 299 | 6.25 |
Drive Mode Mid (Max 15fps)
| Image Type | Shots Before Hitting Buffer | Time to Clear Buffer (Seconds) |
|---|---|---|
| Uncompressed RAW (108.3MB) | 102 | 11.45 |
| Compressed RAW (54.2MB) | 449 | 11.45 |
| Lossless Compressed RAW (59.5MB) | 183 | 6.18 |
| JPEG Extra Fine (26MB) | 474 | 6.70 |
| Uncompressed RAW (108.3MB) + JPEG Extra Fine (26MB) | 84 | 14.16 |
| Compressed RAW (54.2MB) + JPEG Extra Fine (26MB) | 178 | 15.15 |
| Lossless Compressed RAW (59.5MB) + JPEG Extra Fine (26MB) | 100 | 9.63 |
| HEIF (4:2:0) Extra Fine (15.7 MB) | Never hits buffer | < 2.00 |
| HEIF (4:2:2) Extra Fine (18 MB) | Never hits buffer | < 2.00 |
4. ProGrade Digital CFexpress Type A Cobalt
The ProGrade Digital CFexpress Type A Cobalt Memory Card can write up 700MB/s and read up to 800MB/s, so their label speeds are identical to the Sony cards. They are only available in 160GB capacity.
Although not as tough as the Sony cards, they do feature a metal enclosure/encasement that has been designed to endure high temperatures and provide better thermal conductivity.
In-Camera Speed & Buffer Test Results
When shooting uncompressed raw to slot 1 in manual mode/focus with a shutter speed of 1/250th the in-camera write speed is around 600 MB/s.
Here are my in-camera speed test results using a 160GB card:
Drive Mode Hi+ (Max 30fps)
Please note that the maximum speed of 30 fps is only possible in compressed RAW, JPEG and HEIF file formats.
| Image Type | Shots Before Hitting Buffer | Time to Clear Buffer (Seconds) |
|---|---|---|
| Uncompressed RAW (108.3MB) – 20 fps | 87 | 11.46 |
| Compressed RAW (54.2MB) – 30 fps | 152 | 9.90 |
| Lossless Compressed RAW (59.5MB) – 20 fps | 105 | 6.11 |
| JPEG Extra Fine (26MB) – 30 fps | 127 | 7.85 |
| Uncompressed RAW (108.3MB) + JPEG Extra Fine (26MB) – 20 fps | 75 | 14.73 |
| Compressed RAW (54.2MB) + JPEG Extra Fine (26MB) – 30 fps | 117 | 15.03 |
| Lossless Compressed RAW (59.5MB) + JPEG Extra Fine (26MB) – 20 fps | 72 | 9.50 |
| HEIF (4:2:0) Extra Fine (15.7 MB) – 30 fps | 161 | 6.23 |
| HEIF (4:2:2) Extra Fine (18 MB) – 30 fps | 161 | 6.23 |
Drive Mode Hi (Max 20fps)
| Image Type | Shots Before Hitting Buffer | Time to Clear Buffer (Seconds) |
|---|---|---|
| Uncompressed RAW (108.3MB) | 87 | 11.46 |
| Compressed RAW (54.2MB) | 265 | 11.51 |
| Lossless Compressed RAW (59.5MB) | 105 | 6.11 |
| JPEG Extra Fine (26MB) | 210 | 6.95 |
| Uncompressed RAW (108.3MB) + JPEG Extra Fine (26MB) | 75 | 14.27 |
| Compressed RAW (54.2MB) + JPEG Extra Fine (26MB) | 146 | 14.92 |
| Lossless Compressed RAW (59.5MB) + JPEG Extra Fine (26MB) | 85 | 9.75 |
| HEIF (4:2:0) Extra Fine (15.7 MB) | 299 | 6.25 |
| HEIF (4:2:2) Extra Fine (18 MB) | 299 | 6.25 |
Drive Mode Mid (Max 15fps)
| Image Type | Shots Before Hitting Buffer | Time to Clear Buffer (Seconds) |
|---|---|---|
| Uncompressed RAW (108.3MB) | 102 | 11.46 |
| Compressed RAW (54.2MB) | 449 | 11.46 |
| Lossless Compressed RAW (59.5MB) | 183 | 6.18 |
| JPEG Extra Fine (26MB) | 474 | 6.70 |
| Uncompressed RAW (108.3MB) + JPEG Extra Fine (26MB) | 84 | 14.17 |
| Compressed RAW (54.2MB) + JPEG Extra Fine (26MB) | 178 | 15.15 |
| Lossless Compressed RAW (59.5MB) + JPEG Extra Fine (26MB) | 100 | 9.63 |
| HEIF (4:2:0) Extra Fine (15.7 MB) | Never hits buffer | < 2.00 |
| HEIF (4:2:2) Extra Fine (18 MB) | Never hits buffer | < 2.00 |
CFexpress Type-A Readers
If you prefer to take the memory card out of your camera to read, then you will need a CFexpress Type-A memory card reader. Here are some options.
Sony MRW-G2 CFExpress Type-A Card Reader
The Sony MRW-G2 supports both CFexpress Type A cards as well as a SD/SDHC/SDXC cards, along with transfer speeds of up to 10 Gb/s via USB 3.1 Gen 2. Both USB Type-C to Type-C and USB Type-C to Type-A cables are included.
Delkin Devices CFexpress Type A & UHS-II SDXC Memory Card Reader
The Delkin reader features one CFexpress Type A card slot, one UHS-II SDXC card slot and a 10 Gb/s USB 3.2 Gen 2 Type-C interface.
It’s constructed out of anodized aluminum and is also designed with multiple heat sinks to help prevent overheating.
There’s also safe internal storage for one CFexpress Type A card and it comes with a rubber end cover for protection against bumps, impact, water damage, dust, and other forms of debris.
It includes USB Type-C and Type-A cables and is also backward compatible with USB 3.0, 2.0, and 1.1.
Pre-Check Prices & Buyer Reviews for the Delkin Devices CFexpress Type A & UHS-II Reader
At: Amazon | B&H Photo
ProGrade Digital CFexpress Type A & UHS-II SDXC Dual-Slot USB 3.2 Gen 2 Card Reader
The ProGrade Digital reader features one CFexpress Type A slot and one UHS-II SDXC slot, and also supports up to 10 Gb/s via USB 3.2 Gen 2 to deliver transfer speeds of up to 1.25 GB/s, or 1250 MB/s via its USB Type-C interface.
It includes USB Type-C to Type-C and Type-C to Type-A cables.
Summary
The Delkin Devices BLACK & POWER CFexpress Type A cards are marginally faster than the Sony and Prograde cards when shooting uncompressed raw.
But there really isn’t a lot in it. With the Delkin cards shooting 89 uncompressed raw files before hitting the buffer and the Sony and ProGrade cards shooting 87. The Delkin cards clear the buffer a few tenths of a second faster.
However, when shooting JPEG the Sony cards are slightly faster than both the Delkin and Prograde cards.
Ultimately there really isn’t a lot between these cards and you certainly won’t notice the speed difference when shooting in the field.
So I’d simply recommend purchasing whichever are cheaper at the time of purchase.
Check Price & Buyer Reviews for Sony A1
At: Amazon | B&H Photo | Wex Photo UK
Interesting that even the fastest Sony camera can’t reach the the speed limit on the CFexpress type A cards. Makes a nonsense of the critics who decry Sony’s choice of CFexpress type A because CFexpress type B cards are “so much faster” – all that extra speed would go unused when the camera can only write at around 600MB/s.
(to be fair, the cost per gigabyte of CFeB cards is notably lower than CFeA at the moment, though).
There might be heating issues if Sony allowed the cards to write in-camera at their maximum write speeds. From tests on the web with the Canon R5 it looks like this only writes at around 400 MB/s, despite some Type B cards supporting write speeds of up to 1500 MB/s, probably also restricted due to heat issues. I have an R5 as well and I definitely prefer the cost of the Type B cards! Hopefully now that we are seeing a few more manufactures producing Type-A cards the price will come down.
You don’t post often but your content is solid. Thanks for this.
Thanks for that! I’d like to say that I’ll try to post more often but with another kid on the way that might be a challenge! 🙂