Published: January 26, 2017
The Canon EOS 5D Mark IV is the latest update in the venerable 5D series. A new 30.4MP full-frame sensor and Digic 6+ processor are combined with advanced autofocus features from the 1D X Mark II. Its video capabilities have been expanded to include 4K recording at 24 and 30p. The Mark IV provides up to 7fps continuous shooting.
The 5D Mark IV features one CompactFlash and one Secure Digital card slot. The CompactFlash slot supports UDMA7 cards while the Secure Digital slot accepts SD/SDHC/SDXC cards and supports UHS-I. The 5D Mk IV does not support UHS-II cards because it lacks the pins to connect to the high speed interface, however UHS-II cards are backwards compatible and will operate at UHS-I speed in the camera.
A total of 139 memory cards were tested in the camera: 114 SD cards and 25 CF cards. The SD cards include both UHS-I and UHS-II cards, while nearly all CF cards support UDMA7. The results in the tables below show write speed for continuous shooting of RAW images and the number of shots that can be taken in 30 seconds of continuous shooting for RAW+JPEG, RAW and JPEG image modes. Following the results, an analysis provides additional information gathered from the tests. From these tests the fastest SD and CF cards for the 5D Mark IV are provided.
The test uses a manual lens and manual camera settings. The 5D IV is mounted on a tripod and activated using a remote timer. The subject is a detailed test scene illuminated by controlled lighting.
Write speed is calculated using the buffer full condition during extended continuous shooting; the total amount of data written to the card divided by the write time. This calculation provides a more accurate result than the card access light because the the light turns on when the shutter is first activated rather than when the image has been processed and begins writing to the card. Write speed is in megabytes per second MB/s (1 MB = 1,048,576 bytes). Write speed is provided for RAW image mode. Shooting RAW+JPEG and JPEG only result in lower write speed.
The following table shows the number of shots taken in 30 seconds of continuous shooting using the 5D Mark IV. The time does not include the buffer clearing or write time. The test is repeated for three image modes: RAW+JPEG, RAW, and JPEG. The JPEG setting is large, high quality. The camera is set to continuous high drive mode. Average RAW file size is 38.5 MB. Average JPEG file size is 14.0 MB. The detailed test scene used in these tests results in large file sizes. The number of images may be lower than what may be experienced during actual use, depending on the image subject. Images with less detail create smaller file sizes allowing more images to be written in the same time period.
The Canon 5D Mark IV provides UHS-I support including SDR104 mode for high write speed. The camera does not support UHS-II because it lacks the pins to interface the UHS-II bus; however, UHS-II cards can be used in the camera because the cards have the standard SD contacts and revert to UHS-I mode. UHS-II cards offer no speed benefit in the camera compared with fast UHS-I cards, but do provide the ability to download images faster when used in a UHS-II card reader.
As can be seen in the first table, the fastest memory cards in the 5D Mark IV are all CompactFlash cards. In RAW mode the fastest CF cards averaged up to 112 MB/s, while SD cards provided up to about 79MB/s average speed during continuous shooting. These are slightly faster the average speeds measured in the 5Ds, which were 102 MB/s with CF cards and 72MB/s with SD cards.
The buffer capacity of the 5D Mk IV in RAW mode varied from 16 to 21 shots, depending on the memory card. This is the number of shots that can be taken at full frame rate before the frame rate drops. This number changes with different camera settings, image subjects and card write speed. Because the camera writes to the card while it is still shooting, a faster card will clear space and allow more shots at full frame rate. This number is slightly higher than the 15-18 shots of the 5Ds, but the file size in the 5D IV is significantly smaller.
When comparing memory cards it is important to realize that a slow memory card limits the camera after the camera has reached its buffer capacity. At that point the camera only takes additional pictures at the same rate it can write to the card. When using slow SD cards the frame rate dropped to below 0.3 fps when shooting RAW images. The fastest SD cards could sustain about 2 fps, while the fastest CF cards could shoot 3 fps with the buffer at capacity. When shooting JPEG the slowest SD card provided about 36 shots before the frame rate dropped to about 0.6 fps, while fast SD cards could shoot over 100 shots before the frame rate slowed and continued at over 5 fps. With fast CF cards JPG shooting was not limited by the memory card and the high frame rate could be sustained for the 30 second duration of the test.
Since the Canon 5D Mark IV has two card slots, various combinations of using two cards in the camera were tested. In these tests the Lexar Professional 1066x 32GB and SanDisk Extreme Pro 95MB/s U3 32GB cards were used. First, writing to both cards in backup mode the camera was able to capture images up to the speed of the slower of the two cards, in this case it was limited by the SD card. In 30 seconds of shooting the camera captured 47 shots RAW+JPEG, 72 shots RAW and 184 shots JPEG, nearly the same as shooting to the SD card only.
The second test was recording separately, RAW to the CF card and JPEG to the SD card. In this test up to 71 shots were captured in 30 seconds of continuous shooting. This is below the 99 RAW that can be taken when shooting RAW only to the CF card, but above the 67 shots when writing both RAW and JPEG to the CF card.
The fastest memory card in the Canon 5D Mark IV is the Lexar Professional 1066x 128GB CF Card. This card averaged slightly faster write speed but offered similar performance to the 64GB and 32GB capacity versions of the same card. The SanDisk Extreme Pro, Transcend 1000x and Komputerbay 1066x 128GB cards performed nearly as well, all within one shot difference in 30 seconds of continuous shooting. One would be hard pressed to tell the difference in actual use between any of these cards in the 5D Mark IV.
When considering SD cards for the Canon 5D IV the first thing to note is that UHS-II cards offer no speed benefit in the camera. With that in mind, the SanDisk Extreme Pro UHS-I and Lexar Professional 2000x UHS-II cards ended up in a virtual tie for fastest SD card. The difference between these cards can be experienced when downloading images with a UHS-II card reader. The UHS-II card easily outperforms the UHS-I card in read speed. (It should be mentioned that the older SanDisk Extreme Pro UHS-II 32GB SD card did not perform as well as other UHS-II cards because that particular card does not support SDR104 UHS-I bus mode and operates at lower 50MB/s bus speed, whereas the newer Extreme Pro UHS-II microSDXC 64GB card does support the faster SDR104 bus mode.)
The fastest cards in the 5D IV are CF cards. SD cards, especially those that support high write speeds (usually noted as 90MB/s), offer good performance in the camera and are priced lower than similar capacity CF cards. During extended continuous shooting the difference becomes apparent and faster CF cards offer a noticeable improvement over SD cards by clearing the buffer faster and maintaining a higher frame rate after the buffer reaches capacity.
The Canon 5D IV has an integrated USB 3.0 port that allows images to be transferred directly to a computer. To test this transfer method Secure Digital and CompactFlash cards with 7GB of RAW images were used. The camera was connected using a USB 3.0 cable and images were transferred to a fast SSD drive in a computer. The Lexar 1066x 32GB CompactFlash card completed the transfer in 108.5 seconds and averaged 61.2 MB/s. The SanDisk Extreme 95MB/s UHS-I U3 32GB SD card took 185.5 seconds at an average transfer rate of 35.8 MB/s. The CompactFlash transfer rate was just slightly above the 53.4 MB/s speed measured in the 5Ds, however the SD card transfer rate was well below the 65.4 MB/s of the 5Ds.
The preferred method to transfer images when speed is important is to use an external memory card reader. Transfers of RAW images from SD cards using a USB 3.0 card reader typically average 90 MB/s with UHS-I cards and 250 MB/s for UHS-II cards. CompactFlash cards can reach 140MB/s copying actual RAW files using a USB 3.0 card reader. Several card reader tests with various memory cards can be found in the Card Reader Reviews.