Published: February 17, 2017
The Olympus E-M1 Mark II is the new flagship OM-D mirrorless digital camera. The new E-M1 Mk II receives a 20MP sensor and offers a 50MP resolution mode by combining multiple exposures using sensor shift technology. It offers up to 15fps with the mechanical shutter, 18fps with digital shutter and a 60fps burst mode. The built-in 5-axis image stabilization system improves hand-held shooting while the video specifications have been updated to offer up to 4K at 24p. The E-M1 II has dual SD card slots. Only one slot has the high speed UHS-II interface, but all slots accept UHS-II or UHS-I or standard SD cards. UHS-II cards in the second slot will operate at UHS-I speed.
A total of 102 memory cards were tested in the E-M1 II. The results show a distinct performance advantage wen using UHS-II cards. The tables below show the results in write speed for continuous shooting of RAW images and continuous shooting the number of shots in 30 seconds using in three images modes (RAW+JPEG, RAW and JPEG modes) with each SD card. Information about the results is provided in an analysis. The fastest SD cards for the Olympus E-M1 II are selected based on speed in addition to the best value cards recommended for the camera.
The test setup consists of the E-M1 Mark II mounted on a tripod with a remote release timer to actuate the shutter and provide 30 second intervals for the continuous shooting test. All manual settings are used and a manual lens is attached to the camera. Manual focus is fixed on the test subject, a detailed scene with controlled lighting. Write speed is calculated using the buffer-full write condition during continuous shooting. The data written to the card divided by the write time gives the write speed in MB/s (1 MB = 1,048,576 bytes). Results for write speed are for RAW images (RAW+JPEG and JPEG modes result in lower write speed).
The second table shows the number of images that can be taken during 30 seconds of continuous shooting. It does not include the buffer clearing time. The release mode is continuous high and uses the 15fps mechanical shutter setting. Each card is tested in the E-M1 II using RAW+JPEG, RAW and JPEG image modes. The JPEG setting is large, super fine quality. The detailed test scene results in 17.9 MB RAW files and 13.1MB JPEG files.
The E-M1 Mark II card write speed increased significantly compared with the original E-M1. Whereas the E-M1 was limited to 32.5MB/s average write speed, the Mark II averaged 163.4MB/s with the fastest a UHS-II card and 41.7MB/s with the fastest UHS-I card. The UHS-II performance improved since the E-M5 II and PEN-F which failed to average faster than 92MB/s write speed with UHS-II cards. Similar to the E-M5 II and PEN-F, the E-M1 Mark II does not support SDR104 mode (104MB/s bus speed) with UHS-I cards, so its performance using UHS-I cards is limited.
Olympus equipped the E-M1 Mark II with a generous buffer and the ability to capture near twice as many shots as even the recent PEN-F before the buffer limited shooting. It should be noted that buffer capacity depends on camera settings, picture subject and memory card write speed. More detail creates larger file sizes and decrease the apparent capacity in terms of shots. Using a faster card can increase the buffer capacity when shooting continuously because the card clears the buffer during shooting.
During continuous shooting in RAW+JPEG mode the E-M1 II was able to capture up to 60 shots at full frame rate (15fps) with UHS-II cards, up to 54 shots with UHS-I cards and 51 shots with the slowest card. After the buffer reached capacity the frame rate dropped to around 2.7fps with the fastest UHS-II cards, around 1 fps with the fastest UHS-I card, and as low as 0.2 fps with the slowest SD card. Indeed, the generous buffer makes up for card speed when shooting less than 50 frames (or about 3 seconds) continuously.
When shooting RAW, the E-M1 II could reach up to 119 shots at full frame rate with the fastest UHS-II card. Using a UHS-I card dropped this number to 54-60 shots. With the buffer full, the fastest UHS-II card continued to shoot over 9fps with the buffer full, UHS-I cards limited to 2.5 fps the slowest card at 0.6 fps.
In JPEG shooting, the E-M1 II reached 125 shots continuously at full frame rate (15fps) with the fastest UHS-II card before the frame rate dropped, after which it continued to shoot at over 9 fps for the duration of the 30 second test. UHS-I cards managed 66 shots at best before the buffer limited the frame rate, then dropped to 3 fps with faster cards down to 1 fps with the slowest card with the buffer full.
The E-M1 Mark II has two SD card slots which can be used to write different image formats separately to each card or write the same images to both cards. Lexar Professional 2000x UHS-II cards were placed in both slots. Because the second slot does not support UHS-II the card in slot 2 operates in UHS-I mode and was limited to around 41MB/s average write speed.
When writing RAW to slot 1 and JPEG to slot 2, the camera captured 106 shots in 30 seconds. This is less than the 132 RAW+JPEG written to the same card in slot 1 alone in the same time period.
Writing the same images to both cards (backup mode) resulted in essentially the same number of shots as could be captured with the fastest UHS-I card, however RAW+JPEG captured slightly more than expected shots, reaching 90 RAW+JPEG (compared with 82 for the fastest UHS-I card alone), 119 RAW and 145 JPEG. The number of shots was limited by slot 2 which supports only UHS-I write speed at best. When using both slots in backup mode there is no benefit to using a fast UHS-II card in either slot.
Using the Delkin 1900x UHS-II 32GB or Sony M Series UHS-II 64GB cards in slot 1 of the Olympus E-M1 II caused a card error message to appear on the screen. The cards could not be formatted and the camera would not operate with these cards in slot 1. These cards operate without issue in Slot 2, however they are limited to UHS-I speed in the second slot. As previously mentioned, the E-M1 Mark II does not support SDR104 which limits UHS-I performance.
The E-M1 II benefits from UHS-II cards and the fastest card in the camera was the Lexar 2000x UHS-II 64GB. The 163.4 MB/s write speed average was nearly four times the fastest UHS-I card. The top Toshiba and Transcend UHS-II cards also provide excellent performance in the camera. An added benefit of UHS-II cards is their read speeds up to 300MB/s in UHS-II card readers.
While UHS-II cards usually cost significantly more than UHS-I cards, the Lexar 1000x UHS-II cards are an exception. While these cards are limited in write speed (76-77.3 MB/s average in the camera), they perform better than UHS-I cards in the E-M1 II because the camera does not support the fastest UHS-I mode. This gives the Lexar 1000x cards a distinct advantage over the fastest UHS-I cards in the camera and makes them the best value choice. The Lexar 1000x cards also support up to 150MB/s read speed in UHS-II card readers.