The Nikon Z6 II and Z7 II are the definition of “reliable workhorses.” While they don’t demand the extreme sustained speeds of the newer Z8, they have their own unique quirk: The Dual-Slot Bottleneck.
Because these cameras feature one CFexpress Type B slot and one SD UHS-II slot, your card choice determines your entire workflow. If you are a wedding photographer shooting to both cards for backup, your $300 CFexpress card is only as fast as your SD card.
In this guide, I’ve benchmarked the latest cards to help you build the perfect kit—whether you need maximum redundancy for clients or value-focused storage for travel.
Slot 1 supports CFexpress Type-B or XQD memory cards.
Slot 2 can take UHS-II or UHS-I memory cards.
Slot 1: CFexpress Type B (The Primary)
The Z6 II and Z7 II are technically limited by their internal processors, capping write speeds at around 330 MB/s in real-world testing. This means you don’t need the expensive “Diamond” or “Black” series cards designed for the Nikon Z9.

The “Future-Proof” Note: While the Z6 II and Z7 II are CFexpress 2.0 cameras, you can safely use CFexpress 4.0 cards (like the ProGrade Iridium). You won’t see a speed boost in-camera, but your offload speeds to your computer will be twice as fast.
The Smart Buy: I recommend the Lexar Gold Series or Delkin Power. These mid-range cards easily saturate the Z6 II’s buffer but cost significantly less than the flagship models.
| Memory Cards | Review Links | Rating | USB-C Write | USB-C Read | Tested Sustain Speeds | Check Price |
|---|---|---|---|---|---|---|
| CFExpress Type-B | ||||||
| Lexar Diamond CF4.0 128GB-1TB | VPG400 | Amazon / B&H | ||||
| Lexar Diamond 128/256/512GB | Lexar Diamond CFeB Review | VPG400 | 1621 | 1700 | 1565 | Amazon / B&H |
| Lexar Gold CF4.0 512/1TB/2TB | Amazon / B&H | |||||
| Lexar Gold 1TB/2TB | Lexar Gold 1TB-2TB CFeB Review | 1642 | 1695 | 1582 | Amazon / B&H | |
| Lexar Gold 128/256/512GB | Lexar Gold 128-512GB CFeB Review | 1410 | 1525 | 1382 | Amazon / B&H | |
| Lexar Silver CF4.0 256/512GB/1/2TB | Amazon | |||||
| Prograde Iridium CF4.0 400GB | VPG400 | 2704 | 3212 | 808 | Amazon / B&H | |
| ProGrade Gold CF4.0 256GB/512GB | 2545 | 3203 | 844 | Amazon / B&H | ||
| Delkin Black CF4.0 325/650GB | 1736 | 2476 | 1693 | Amazon / B&H | ||
| Delkin Power G4 128/165/256/325/2TB | Delkin Power 128-512GB G4 CFeB Review | 920 | 1226 | 842 | Amazon / B&H | |
| Hoodman Steel 1TB | Hoodman Steel 1TB CFeB Review | 1528 | 1121 | 1502 | Amazon / B&H | |
| Angelbird Pro XT Mk II 330/660/1320GB | 1595 | 1597 | 1583 | Amazon / B&H | ||
| Nextorage B2 Pro CF4.0 660/1330GB | VPG400 | B&H | ||||
| Nextorage B2 Pro CF4.0 165/330GB | VPG400 | B&H |
Occasionally, some CFexpress cards in Nikon Z6, Z7, Z8, and Z9 series cameras are a little tight. I’ve had this happen with Angelbird and OWC cards. However, this has been improved with the Nikon Z6 III.
Slot 2: SD UHS-II (The Bottleneck)
This is where most Z6 II owners make a mistake. If you set your camera to “Backup” mode, it waits for the SD card to finish writing before letting you shoot again.

For Backup Shooters (Weddings/Events): You must use a V90 card. Something like a Sony G Tough V90 or SanDisk Extreme Pro V90 is essential here. A slower V60 card will cripple your buffer depth, making your fast CFexpress card useless.
For Overflow/Video Shooters: If you only use the SD slot when the CFexpress is full, or just for H.264 video, you can save money with a V60 card like the Lexar Silver Pro. It runs cooler and offers twice the storage for the same price.
| Recommended SD UHS-II Memory Cards | Review Links | Speed Class | Minimum Write Speed | USB-C Write | USB-C Read | Check Price |
|---|---|---|---|---|---|---|
| SD UHS-II V90 | Hide | |||||
| Sandisk Extreme Pro V90 32-512GB | Sandisk Extreme Pro V90 UHS-II Review | UHS-II v90 | 90 | 268 | 293 | Amazon / B&H |
| Lexar 2000x V90 32-256GB | Lexar 2000x V90 UHS-II Review | UHS-II v90 | 90 | 228 | 256 | Amazon / B&H |
| Sony G Tough v90 32-256GB | Sony G Tough V90 UHS-II Review | UHS-II v90 | 90 | 258 | 296 | Amazon / B&H |
| Delkin Black v90 64/128/256GB | UHS-II v90 | 90 | 253 | 278 | B&H | |
| Kingston Canvas React V90 32-256GB | Kingston Canvas React Plus V90 | UHS-II v90 | 90 | 274 | 292 | Amazon / B&H |
| SD UHS-II V60 | Hide | |||||
| Sandisk Extreme Pro v60 256/512/1TB | UHS-II v60 | 60 | 189 | 279 | Amazon / B&H | |
| Lexar ARMOR Gold V90 256GB/1TB | UHS-II v60 | 60 | 191 | 258 | Amazon / B&H | |
| Sony M Tough V60 64-512GB | Sony M V60 UHS-II Review | UHS-II v60 | 60 | 153 | 269 | Amazon / B&H |
| Sony E v60 256GB | Sony E Series V60 256GB Review | UHS-II v60 | 60 | Amazon / B&H |
Best CFexpress Reader
I’ve been benchmarking these cards with the ProGrade CFexpress + UHS-II reader. The Lexar reader is slightly faster if you just need a reader for CFexpress cards, although the difference isn’t really noticeable in real-world file transfers.
Prograde CFexpress + UHS-II Reader – Amazon / B&H – This reader will not read XQD cards, but it is my favorite because of the magnetic base that lets me stick it to my desk or computer.
If you buy an Angelbird card, you should also buy an Angelbird reader to upgrade the cards’ firmware.
Also, see the Guide To The Best Accessories for the Nikon Z6 II and Z7 II.
Memory Card Benchmarks
Continuous burst images were taken to benchmark each memory card in the Nikon Z6 II and Z7 II until the buffer was filled. Then, the time required to clear the buffer was measured against the amount of data written. This gave me a rough speed of how each card is performing in-camera. I ran several series with each card to rule out issues or other hiccups that sometimes occur with freshly formatted cards.
There was significant wild variation in the Nikon Z6 II. Many V90 UHS-II cards were not engaging that second set of pins and ran at UHS-I speeds. I am told this is a problem with the camera firmware, so just stick with the cards posting good scores.
CFexpress & SD Memory Cards For Nikon Z6 II & Z7 II
To see how each card runs with a Thunderbolt reader for faster speeds, check out the guide for the Best CFexpress Type B cards.

Can I still use XQD?
Yes, and for the Z6 II / Z7 II, XQD cards are still perfectly viable.
If you are upgrading from a D850 or original Z6 and already own Sony G or Nikon XQD cards, keep using them! The speed difference between XQD (approx. 220 MB/s) and the camera’s max write speed (330 MB/s) is noticeable but not earth-shattering for single-shot work. Save your money for good glass instead.
Video Requirements: 4K/60p and Heat
Unlike the Z6 III, the Z6 II tops out at fairly modest bitrates (approx. 144 Mbps for 4K/60p).
The “Why” for CFexpress: However, for long-form interviews or events, I still recommend recording video to the CFexpress slot. The cards are physically larger and dissipate heat much better than plastic SD cards, reducing the risk of overheating warnings during long takes.
The Reality: You technically don’t even need CFexpress for video; a V30 SD card covers the data rate.
Choosing the Right Size: 128GB is the New Minimum
When buying media for the Z6 II and Z7 II, you aren’t just buying storage space; you are buying durability and considering the long-term use implications. I’ll explain.
- The “Wear-Leveling” Factor: Flash memory wears out the more you write to it. A 512GB card will theoretically last 4 times as long as a 128GB card because the controller has more fresh blocks to cycle through. For professional use, over-buying capacity is a smart long-term investment.
For the Nikon Z6 II (24MP)
- Photography: A 128GB card is the sweet spot. It holds over 2,500 Lossless Compressed RAWs, which is more than enough for a typical wedding or event.
- Hybrid/Video: If you shoot 4K video, bump up to 256GB. This gives you plenty of headroom for a full day of mixed media without needing to swap cards in the field.
For the Nikon Z7 II (45MP)
Recommendation: Start at 256GB for photography. If you are going on a landscape trip or some serious travel where you might be away from a computer for days, a 512GB or 1TB CFexpress card can be very useful, giving you a ton of peace of mind. Although I would still back up the card regularly, just in case something happens.
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Good post. I had similar results in my more limited testing with a D850, Z6, and Z7ii.
As people look at different cards, one thing to keep in mind is these test results are for the specific model and size card referenced. Smaller cards can be significantly slower, and in some cases larger cards are faster. Generation of the card also matters – some cards have been updated and early models of that card may be slower. All this assumes you are running the most recent firmware for your camera.
One simple test I’ve used is to shoot a 35 second burst and then count the frames in each full second. All cards are the same at peak frame rate for the initial burst, and then the camera slows to write speed. In some cases slower cards were much slower after the first 6-7 seconds. I looked at sustained speeds and variation operating with a full buffer. Cards like the ProGRade Gold 128GB CF Express B were much slower and more variable during the 7-35 second portion of a burst. I also found it more useful to test with 14 bit lossless compressed RAW because that’s how I shoot. The time lost for compression more than offsets the larger files of uncompressed RAW so you write more FPS with lossless compressed files.
One other finding I had in testing is you need to freshly format a card when you change cameras. Cards formatted in one camera and then used in a different camera usually work, but in my testing the speeds were much slower than speeds achieved after fresh formatting.