Published: March 10, 2015
The Olympus E-M5 Mark II represents several notable advances in the Micro Four Thirds OM-D line. First, it brings a new high resolution option by using the 5-axis image stabilization system to shift the 16 megapixel sensor and combine eight images into one 40 megapixel JPEG or 64 megapixel RAW image. Second, the E-M5 II provides bursts up to 10fps (mechanical shutter) and 11fps (silent electronic shutter) and supports the new high speed UHS-II memory card interface. With its improved processing and UHS-II SD cards the E-M5 II can capture RAW images continuously at 5fps until the card is full.
To test memory card performance in the E-M5 II, 43 SD cards including both UHS-I and UHS-II were used in the camera. The cards are compared in write speed for continuous shooting of RAW images. The results are shown in the first table. The second table shows the number of images captured during continuous shooting for 30 seconds in three different image types: RAW+JPEG, RAW and JPEG modes. An analysis is provided with observations from the tests. Finally, specific SD cards are recommended for the E-M5 II, including fastest card and best value card for this camera.
Tests are performed with the E-M5 II mounted on a tripod. Manual focus is set with live view at maximum magnification. The test target is a detailed test scene under controlled lighting. A remote shutter release is used for 30 second intervals. Write speed is calculated using the total bytes written to each card divided by the total write time. Write speed is measured in MB/s (1 MB = 1,048,576 bytes). The write speed results are for RAW image format (RAW+JPEG and JPEG modes provide lower write speed).
Continuous shooting is a measurement of how many images can be taken in a 30 second interval. Three image modes are used: RAW+JPEG, RAW, and JPEG. JPEG are large, super fine quality. The E-M5 II is set to continuous high release mode 10fps (mechanical shutter). The detailed subject in this test produces 15.1 MB RAW files and 11.1MB JPEG files.
The E-M5 II shows a significant increase in write speed compared with the original E-M5. The highest write speed in the Mark II was 82.3MB/s, while the fastest speed measured in the E-M5 was 28.6MB/s (E-M5 SD card comparison). To get the highest write speed, UHS-II cards must be used. All UHS-I cards tested were limited to below 40MB/s write speed. It would seem the E-M5 II card controller does not support SDR104, the fastest bus speed mode provided by UHS-I (104MB/s).
In continuous shooting in RAW+JPEG, the E-M5 II was able to capture 14 to 15 shots at full frame rate. The UHS-II cards were fast enough to allow a one shot advantage. After the buffer reached capacity, the frame rate dropped to around 3fps with the fastest UHS-II cards, around 1.6 fps with the faster UHS-I cards, and as low as 0.45 fps with the slowest card.
In RAW mode, the E-M5 II reached 14-16 shots with UHS-I cards, and up to 23 shots with the fastest UHS-II cards before the frame rate dropped. True to Olumpus' marketing claim that the E-M5 II can support unlimited 5fps shooting, with the buffer full it continued to shoot at 5.6 fps for the duration of the 30 second test when using the fastest UHS-II card. The Lexar 1000x UHS-II card reached 4.7 fps, while fast UHS-I cards could only sustain 2.7 fps for the duration (with the buffer full). The slowest card could only manage 0.8 fps with the buffer full.
When shooting JPEG, the E-M5 II could reach up to 30 shots at full frame rate. The UHS-II cards provided 28-30 shots, while UHS-I cards varied from 19-24 shots. The fastest UHS-II card allowed 6.9 fps with the buffer full, the slowest card just over 1 fps. It should be emphasized that these numbers depend on camera settings and the image subject. A less detailed subject will create smaller image files and clear the buffer faster thereby allowing a higher continuous frame rate after the buffer has reached capacity.
Those who desire the highest performance for the E-M5 II should consider UHS-II memory cards. Actual write speeds of UHS-II cards measured twice as fast as the fastest UHS-I cards. The fastest card was the Lexar Professional 2000x UHS-II that reached 82.3 MB/s continuous write speed in the E-M5 II. It also allowed the most shots at full frame rate and sustained the highest frame rate with the buffer full. The Toshiba Exceria Pro and SanDisk Extreme Pro 280MB/s UHS-II cards also provide very high performance. An added benefit of UHS-II cards is their read speed for downloading images that can reach above 200MB/s in a UHS-II card reader.
The best value SD card for the E-M5 II is the Lexar Professional 1000x UHS-II. It performed significantly better than fast UHS-I cards, without the high price. The Lexar 1000x also supports up to 150MB/s read speed when used in a UHS-II card reader.
A majority of the UHS-I cards tested performed similarly due to the E-M5 II's limited write speed in UHS-I mode. While the SanDisk Extreme Pro 95MB/s UHS-I 64GB SDXC Card is a very fast card, it is not worth the premium price when the Extreme 60MB/s card provided practically the same performance in the E-M5 II at a fraction of the cost.
The E-M5 II provides a USB port to transfer images from the camera using USB 2.0. To test download speed, over 4GB of RAW files were copied from the camera to a computer equipped with a SSD drive. The fastest transfers measured 27MB/s (2.6 minutes) with the camera in MTP mode and 14MB/s (6 minutes) in Storage mode.
When speed matters, a USB 3.0 card reader can provide much faster downloads. The Lexar 2000x UHS-II card transferred the the same files at 180MB/s in 23 seconds. (Transferring separate, smaller files results in lower average transfer speeds compared with benchmarks.) Check out the Card Reader Reviews for additional tests and information.