The extreme resolution of today’s cameras, coupled with their ability to capture high FPS photos and up to 8K video, places huge demands on the speed of memory cards. If you’ve ever had to wait dozens of painful seconds for the buffer to empty, you’ll know what I’m talking about. For this reason, I tested memory cards from different parts of the price spectrum directly in Nikon cameras – including CFExpress, XQD, and SD cards – to show you which ones are the fastest.
Memory card manufacturers know how important speed is, which is why they proudly proclaim the read and write speeds glowing in gold lettering on the box. In an ideal world, these numbers would make for the perfect buying guide. But we live in the real world, where the information written on the box does not always mean very much.
Are manufacturers trying to lie to us? I would like to think not. However, their test conditions are far from the real world. That’s why I decided to find out the practical read and write speeds for myself.
For now, I have tested the 31 memory cards below. I will expand this real-life speed ranking every time I use a new memory card in the future.
How I Tested
I performed the tests below using a Nikon Z9 or Nikon Z8 coupled with a 50mm f/1.8 lens. Both cameras have the same maximum frame rate, the same buffer capacity, and the same file sizes. The advantage of the Z8 is that it also allows you to test SD cards. I set lossless compressed RAW (average file size 54.8MB), 1/1000s, f/2.8, and continuous shooting at the highest rate of 20 FPS. I shot the test scene for 60 seconds. This was repeated for five different test scenes to minimize the measurement error and the effect of the scene on the file size.
To measure read speed, I used my MSI Creator Z16 laptop (Intel Core i9, Geforce RTX 3060, USB3.2 Gen2 ports). For the connection between the card and the laptop, I used Exascend USB 3.2 Gen 2 Dual-Slot Readers (CFExpress B and SD cards) and Lexar Professional XQD 2.0 USB 3.0. For testing I used the EaseUS DiskMark application. Again, I took 5 measurements and then averaged the results.
I did not test the cards’ ability to resist overheating, nor did I measure their speed as a function of temperature. This measurement would certainly be very interesting, but would require strictly standardized conditions, which are not easy to achieve. The original Nikon MC-CF660G CFexpress Type B, the Delkin Devices 325GB BLACK CFexpress Type B or the ProGrade Digital 650GB CFexpress 2.0 Type B Cobalt cards are reported to give very good results in this respect. So, if you plan to use the card primarily for 8K raw video recording, you should consider this feature as well, in addition to speed.
The Results
In the first few seconds of high-FPS shooting, I did not notice any significant differences between the different cards. This is due to the relatively deep buffer of the Nikon Z9 and Z8. However, once the buffer is full, the differences become apparent, as the slowest cards immediately grind to a halt. On the worst card I tested, the frame rate after the first few seconds dropped precipitously, and the average speed over 60 seconds was a mere 1.9 FPS.
With that, let’s get into the tests.
Declared write speed: 1500 MB/s
Declared read speed: 1700 MB/s
Average measured write speed: 854.9 MB/s
Average measured frame rate: 15.6 fps
Suitable for 8K video: Yes
Regular price: $726
#2 ProGrade Digital 650GB CFexpress 2.0 Type B Cobalt
Declared write speed: 1500 MB/s
Declared read speed: 1700 MB/s
Average measured write speed: 847.6 MB/s
Average measured frame rate: 15.5 fps
Suitable for 8K video: Yes
Regular price: $540
#3 Delkin Devices 150GB BLACK CFexpress Type B
Declared write speed: 1530 MB/s
Declared read speed: 1725 MB/s
Average measured write speed: 843.9 MB/s
Average measured frame rate: 15.4 fps
Suitable for 8K video: Yes
Regular price: $180
Where to buy: B&H
#4 Delkin Devices 325GB BLACK CFexpress Type B
Declared write speed: 1530 MB/s
Declared read speed: 1725 MB/s
Average measured write speed: 839.9 MB/s
Average measured frame rate: 15.3 fps
Average measured read speed: 1067.0 MB/s
Suitable for 8K video: Yes
Regular price: $425
Where to buy: B&H
#5 Delkin Devices 128GB POWER CFexpress Type B
Declared write speed: 1700 MB/s
Declared read speed: 1780 MB/s
Average measured write speed: 832.4 MB/s
Average measured frame rate: 15.2 fps
Average measured read speed: 1055.6 MB/s
Suitable for 8K video: Yes
Regular price: $110
#6 Delkin Devices 256GB BLACK CFexpress Type B
Declared write speed: 1400 MB/s
Declared read speed: 1645 MB/s
Average measured write speed: 831.0 MB/s
Average measured frame rate: 15.2 fps
Average measured read speed: 821.3 MB/s
Suitable for 8K video: Yes
Regular price: $_ _
Where to buy: No Longer Available
#7 Exascend Essential CFexpress B 1TB
Declared write speed: 1700 MB/s
Declared read speed: 1800 MB/s
Average measured write speed: 805.6 MB/s
Average measured frame rate: 14.8 fps
Average measured read speed: Not measured (to be added)
Suitable for 8K video: Yes
Regular price: $469
#8 ProGrade Digital 325GB CFexpress 2.0 Type B
Declared write speed: 1500 MB/s
Declared read speed: 1700 MB/s
Average measured write speed: 804.3 MB/s
Average measured frame rate: 14.7 fps
Average measured read speed: 1033.2 MB/s
Suitable for 8K video: Yes
Regular price: $450
#9 Delkin Devices 325GB BLACK G4 CFexpress Type B
Declared write speed: 1700 MB/s
Declared read speed: 1800 MB/s
Average measured write speed: 804.3 MB/s
Average measured frame rate: 14.7 fps
Suitable for 8K video: Yes
Regular price: $280
Where to buy: B&H
#10 ProGrade Digital 512GB CFexpress 4.0 Type B Gold
Declared write speed: 2400 MB/s
Declared read speed: 3400 MB/s
Average measured write speed: 762.6 MB/s
Average measured frame rate: 13.9 fps
Suitable for 8K video: Yes
Regular price: $180
Where to buy: B&H
#11 Nextorage 165GB NX-B1PRO Series CFexpress Type B
Declared write speed: 1900 MB/s
Declared read speed: 1950 MB/s
Average measured write speed: 759.3 MB/s
Average measured frame rate: 13.9 fps
Average measured read speed: 1034.7 MB/s
Suitable for 8K video: Yes
Regular price: $170
#12 Wise Advanced 1TB CFX-B Series Mark II CFexpress Type B
Declared write speed: 1550 MB/s
Declared read speed: 1700 MB/s
Average measured write speed: 748.9 MB/s
Average measured frame rate: 13.7 fps
Average measured read speed: 600.8 MB/s
Suitable for 8K video: Yes
Regular price: $400
Where to buy: B&H.
#13 Delkin Devices 128GB POWER G4 CFexpress Type B
Declared write speed: 1700 MB/s
Declared read speed: 1780 MB/s
Average measured write speed: 719.4 MB/s
Average measured frame rate: 13.1 fps
Suitable for 8K video: Yes
Regular price: $110
#14 Wise Advanced 512GB CFX-B Series Mark II CFexpress Type B
Declared write speed: 1550 MB/s
Declared read speed: 1700 MB/s
Average measured write speed: 619.2 MB/s
Average measured frame rate: 11.3 fps
Average measured read speed: 603.2 MB/s
Suitable for 8K video: Yes
Regular price: $200
Where to buy: B&H.
#15 Nextorage 512GB NX-B2SE Series CFexpress Type B
Declared write speed: 1900 MB/s
Declared read speed: 1950 MB/s
Average measured write speed: 581.5 MB/s
Average measured frame rate: 10.6 fps
Average measured read speed: 1034.2 MB/s
Suitable for 8K video: Yes
Regular price: $175
Where to buy: Adorama and Amazon.
#16 Lexar 256GB Professional CFexpress Type B Card SILVER Series
Declared write speed: 1300 MB/s
Declared read speed: 1750 MB/s
Average measured write speed: 511.8 MB/s
Average measured frame rate: 9.3 fps
Suitable for 8K video: Yes
Regular price: $140
#17 SanDisk 128GB Extreme PRO CFexpress Type B
Declared write speed: 1200 MB/s
Declared read speed: 1700 MB/s
Average measured write speed: 427.6 MB/s
Average measured frame rate: 7.8 fps
Average measured read speed: 1064.2 MB/s
Suitable for 8K video: No
Regular price: $110
#18 Sony 64GB G Series XQD
Declared write speed: 400 MB/s
Declared read speed: 440 MB/s
Average measured write speed: 355.1 MB/s
Average measured frame rate: 6.5 fps
Average measured read speed: 355.5 MB/s
Suitable for 8K video: No
Regular price: $90
#19 Nikon XQD 64GB
Declared write speed: 400 MB/s
Declared read speed: 440 MB/s
Average measured write speed: 352.7 MB/s
Average measured frame rate: 6.4 fps
Average measured read speed: 402 MB/s
Suitable for 8K video: No
Regular price: $160
Where to buy: Amazon.
#20 Lexar XQD 32GB 2933x Professional
Declared write speed: 400 MB/s
Declared read speed: 440 MB/s
Average measured write speed: 351.1 MB/s
Average measured frame rate: 6.4 fps
Average measured read speed: 361.3 MB/s
Suitable for 8K video: No
Regular price: $_ _
Where to buy: No Longer Available
#21 Delkin Devices 256GB POWER CFexpress Type B
Declared write speed: 1700 MB/s
Declared read speed: 1780 MB/s
Average measured write speed: 351.0 MB/s
Average measured frame rate: 6.4 fps
Average measured read speed: 473.9 MB/s
Suitable for 8K video: Yes
Regular price: $135
Where to buy: B&H.
#22 Nextorage 128GB NX-F2PRO Series UHS-II SDXC
Declared write speed: 299 MB/s
Declared read speed: 300 MB/s
Average measured write speed: 252.1 MB/s
Average measured frame rate: 4.6 fps
Suitable for 8K video: No
Regular price: $110
#23 ProGrade Digital 256GB UHS-II SDXC
Declared write speed: 250 MB/s
Declared read speed: 300 MB/s
Average measured write speed: 242.3 MB/s
Average measured frame rate: 4.4 fps
Suitable for 8K video: No
Regular price: $202.5
Where to buy: B&H
#24 ProGrade Digital 128GB UHS-II SDXC
Declared write speed: 250 MB/s
Declared read speed: 300 MB/s
Average measured write speed: 239.3 MB/s
Average measured frame rate: 4.4 fps
Suitable for 8K video: No
Regular price: $109
#25 Sony 64GB SF-G TOUGH Series UHS-II SDXC
Declared write speed: 299 MB/s
Declared read speed: 300 MB/s
Average measured write speed: 236.4 MB/s
Average measured frame rate: 4.3 fps
Average measured read speed: 94.3 MB/s
Suitable for 8K video: No
Regular price: $100
#26 SanDisk 64GB Extreme PRO UHS-II SDXC
Declared write speed: 260 MB/s
Declared read speed: 300 MB/s
Average measured write speed: 222.5 MB/s
Average measured frame rate: 4.1 fps
Average measured read speed: 94.5 MB/s
Suitable for 8K video: No
Regular price: $65
#27 ProGrade Digital 128GB CFexpress 2.0 Type B Gold
Declared write speed: 1400 MB/s
Declared read speed: 1700 MB/s
Average measured write speed: 202.5 MB/s
Average measured frame rate: 3.7 fps
Suitable for 8K video: No
Regular price: $100
#28 OWC 128GB Atlas Pro CFexpress Type B
Declared write speed: 1400 MB/s
Declared read speed: 1700 MB/s
Average measured write speed: 198.5 MB/s
Average measured frame rate: 3.6 fps
Suitable for 8K video: No
Regular price: $_ _
Where to buy: No Longer Available
#29 SanDisk 64GB Extreme PRO SDXC UHS-I (95MB/s)
Declared write speed: 90 MB/s
Declared read speed: 95 MB/s
Average measured write speed: 108.1 MB/s
Average measured frame rate: 2.0 fps
Suitable for 8K video: No
Regular price: $34.5
Where to buy: Amazon.
#30 SanDisk 64GB Extreme PRO UHS-I SDXC
Declared write speed: 90 MB/s
Declared read speed: 200 MB/s
Average measured write speed: 106.5 MB/s
Average measured frame rate: 1.9 fps
Average measured read speed: 95.6 MB/s
Suitable for 8K video: No
Regular price: $13.49
#31 SanDisk 32GB Extreme PRO SDXC UHS-I (95MB/s)
Declared write speed: 90 MB/s
Declared read speed: 95 MB/s
Average measured write speed: 102.3 MB/s
Average measured frame rate: 1.9 fps
Suitable for 8K video: No
Regular price: $16
Where to buy: Amazon.
Analysis
What stood out to me was the dramatic difference between CFExpress Type B, XQD, and SD cards. Indeed, CFExpress Type B cards are the speed champions compared to the other card types. At the same time, it turns out that even in this category, it pays to choose carefully. While the best of the cards tested averaged around 15 FPS at 60 seconds of high-speed shooting, there were a few outliers whose speed was shockingly slow.
The speed of a pair of OWC 128GB Atlas Pro CFexpress Type B and ProGrade Digital 128GB CFexpress 2.0 Type B Gold cards (around 3.7 FPS) was far behind the XQD cards and even all SDXC UHS-II cards. For a similar price, you can buy, for example, the more than four times faster Delkin Devices 128GB POWER CFexpress Type B. And believe me, you can really feel the speed difference. The SanDisk 128GB Extreme PRO CFexpress Type B card was also far behind expectations with a speed of 7.8 FPS.
I was also surprised by the inconsistency of card speeds within a single model series. While the aforementioned Delkin Devices 128GB POWER CFexpress Type B (previous generation) was one of the absolute top performers, its 256GB sibling was a complete flop in the test. This particular card also failed me for good when I was shooting in Ecuador. So, as in life, I recommend not putting all your eggs in one basket.
A very interesting result was achieved by potentially the fastest card in the test, the ProGrade Digital 512GB CFexpress 4.0 Type B Gold. It is the only one in the test that already runs on the new CFexpress 4.0 standard. Unfortunately, none of the cameras on the market today can take advantage of the blazing speeds it promises because they lack CFexpress 4.0 support. Its result of 13.9 FPS on the Nikon Z9 is actually below average among similar cards (ranking 10th place among the cards tested here). However, the price/performance ratio is very good, and with a compatible reader, you get a future-proof card that allows you to enjoy fast transfer speeds today.
Taking price into account, I was also impressed by the Exascend Essential CFexpress B 1TB card. This card has a huge capacity and a frame rate of 14.8 FPS, which is almost at the level of the winner of the test. All this for a price of $469, which is among the best price/capacity ratio of all cards tested.
The XQD cards hovered around 6.4 FPS. However, I would not recommend buying them today due to the unfavorable price/performance ratio. The only reason to buy them is if you have a camera that does not support CFExpress Type B cards, such as the Nikon D4. The UHS-II SD cards were about 4.2 FPS, while the UHS-I card I tested achieved a mere 1.9 FPS. However, UHS-I cards can be purchased very cheaply, so if speed is not a priority, this may be the way to go.
As the range of cards used in Nikon cameras has expanded with the Zf to include microSD, I’ll be expanding our test to include them soon. Let me know what cards you would like me to test next!