Your guide to selecting the fastest CF Express Cards for the Nikon Z9 and any other camera that requires fast write speeds.  This will be particularly important for photographers who shoot action such as sports or wildlife.

In depth testing of the Nikon Z9 has demonstrated very clearly that not all CF Express cards are capable of keeping up with the speed the Nikon Z9 requires when writing data to the memory card.  Choosing the wrong CF Express card will mean that your buffer will fill more quickly and as a result you could be missing key moments during crucial action bursts.

What Are The Fastest CF Express Cards?

  1. Delkin Black 128 GB  – Min Write Speed 1710 MB/s – B&H $229.99
  2. ProGrade 325GB Cobalt – Min Write Speed 1400 MB/s – B&H $399.99
  3. Wise 640 Pro 640 GB – Min Write Speed 1400 MB/s – B&H $749.99

The CF Express cards listed above have been field tested on a Nikon Z9 pre-production camera.

What to Look For When Choosing a CF Express Card for the Nikon Z9

(Note: All Information Below Applies to Any Camera Requiring Fast Write Speeds)

Look for TYPE B CF Express cards that guarantee a MINIMUM WRITE SPEED OF 1400 Mb/s.  Many CF Express cards advertise high read speeds but don’t be fooled.  Fast MINIMUM WRITE SPEED is the only thing that matters to the Nikon Z9 when writing data to the card.

Having said that, even CF Express cards that advertise write speeds of 1400 Mb/s and higher may not deliver.  Note, the keyword MINIMUM is missing from that advertising label and that’s the most important variable when shopping for a CF Express card.

So how do you know which CF Express card to buy?  I’m going to make it easy on you and list the CF Express cards that have been field tested and proven to perform so you can purchase with confidence.

Which CF Express Cards Are Fast Enough For The Nikon Z9?

The following CF Express cards have been FIELD TESTED AND PROVEN to deliver the blazingly fast write speeds the Nikon Z9 requires to clear its buffer quickly.

1. ProGrade Digital 325GB CFexpress 2.0 Type B Cobalt Memory Card. Available at B&H $399.99.

Prograde Digital CF Express Memory Card









Delkin Devices 256GB BLACK CF Express Type B Memory Card.  Available at B&H $379.00.
Delkin Black CF Express

Delkin Devices advertises minimum write speeds from 1400 MB/s all the way up to 1710 MB/s.  Did you know that minimum write speeds may vary by capacity across manufacturers?  Delkin Devices is one such manufacturer.  This is not a bad thing, just something to be aware of when shopping for a new CF Express card.  See the table further below in this post to see what I am referring to.

Note: Due to manufacturing delays, both the Delkin and Prograde cards have been in and out of stock like a yo-yo.  My best advice is to add your name to the B&H Request Stock Alert to be notified when stock is available and purchase as soon as you receive the alert.

I will add to this list as further testing of other cards is completed.

CF Express Cards Advertising Minimum Write Speed Guarantees | Not Yet Field Tested

Angelbird 660GB AV Pro XT CF Express Type BAdvertised Minimum Write Speed 1480 MB/s – B&H 2 Pack $969.99

Angelbird 330 AV Pro CF Express XT Card



Sony Tough Cards – Do They Measure Up For Action?

Sony Tough CF Express Type B – B&H $429.99

Sony Tough CF Express Memory Card









I was very surprised to learn in testing that the more expensive Sony Tough CF Express card DID NOT perform as well as the Prograde Cobalt card or the Wise 640 Pro.  Sony advertises a write speed of 1480 MB/s which is great at first glance.  I looked through Sony’s documentation for their Type B Tough CF Express card and they mention the 1480 MB/s write speed several times.

I was not able to find a minimum write speed in their literature.  You’ll soon see why that minimum write speed guarantee is so important when purchasing a CF Express card for the Nikon Z9.  Of course, the same holds true for any other brand of camera that requires fast write speeds.

The proof is in the testing.  Head on over to the link below which is a CF Express card write speed comparison video done by Matt Granger using a prototype Nikon Z9.  He performs tests on 13 memory cards to determine how many shots he can take before the buffer fills.

Matt Granger CF Express Card Comparison Video

Matt Granger CF Express Video


For those of you who just want a quick summary, Matt has provided a table below which details the results for the 13 memory cards he tested.  Matt shot the Nikon Z9 on five diiferent RAW formats and has presented his findings for each one across the top of the displayed table.

For action photographers who enjoy sports and wildlife, you’re really going to want to pay attention to the minimum write speeds especially in Lossless RAW and High Efficiency Star Raw.  Those are the two modes I expect most of you will be shooting, especially for wildlife where we care a lot about maximum detail in our images.

Matt Granger CF Express Table



Don’t Be Fooled By CF Express Write Speed Labels

The learning from this test is that you can not simply go by the a CF Express cards label.  Sony’s label shows a write speed of 1480 MB/s and ProGrade’s is 1500 MB/s.  Those two numbers are not significantly different are they?  The difference is that Prograde provides a minimum write speed guarantee of 1400 MB/s and Sony does not appear to.  This difference shows up in a big way during testing.

Prograde CF Express Memory Card Minimum Speed Guarantee





Minimum Write Speed Can Change With Capacity

Another variable for your consideration is capacity.  Be aware that minimum write speeds can vary depending on the capacity of the card.  As shown in the table below, the minimum write speeds for Delkin Black cards vary widely.

In the case of Delkin Black cards, if you wanted the fastest minimum write speed available you’d want to purchase the 128 GB card with a minimum write speed of 1710 MB/s.

Delkin Black Min Speed Table


CF Express Cards Not As Fast As The Rest

The CF Express cards listed below may work with the Nikon Z9 and they may be fast enough for the type of photography that you do.  It all depends on how fast you need to write to your card to clear the buffer.  As stated above, if you shoot action it makes sense to purchase the fastest MINIMUM write speed card available.

Angelbird 256 GB CF Express Type BMaximum write speeds up to 1500MB/s.  Advertised sustained write speed is 550 MB/s. Available at B&H $199.99

Hoodman Steel 256GB CF Express Memory CardMaximum write speeds up to 1400 MB/s.  No minimum advertised. Available at B&H $369.95

SanDisk Extreme PRO 256GB CF Express Card Type B Maximum write speeds up to 1200 MB/s.  No minimum advertised. Available at B&H $399.99

Lexar Professional 256GB CF Express Type-B  – Maximum write speeds up to 1000 MB/s. Available at B&H $399.99

Wise Advanced 256GB CFexpress Type BMaximum write speeds up to 1050 MB/s. Available at B&H $292.49

CF Express Card Reader

You will need a CF Express Card Reader to offload your images to your computer.  Since I also own the Nikon Z6II and Nikon Z7II I purchased a card reader that can read not only the CF Express cards but also the SDXC cards.  No sense purchasing two readers when one combo reader will do.

Available at B&H: Digital CF Express Type B & UHS-II SDXC Dual-Slot USB 3.2 Gen 2 Card Reader $79.99

 Prograde Dual CF Express SDXC Card Reader