Camera Memory Speed
Memory Card Comparison & Performance Tests for Digital Cameras
Sony Alpha A9 dual SD card slot door open

Fastest SD cards for the Sony A9

Published: June 20, 2017

The Sony A9 is an advanced professional-level mirrorless digital camera. It features a full-frame 24.2MP stacked CMOS sensor with back side illumination. It is capable of delivering up to 20fps continuous shooting with autofocus and tracking. The stacked sensor is a first for a full-frame sensor and allows ultra-fast readout for reduced rolling shutter in video. The sensor offers ISO to 51,200 and expanded range reaches 204,800. The A9 can shoot 4K video in 24 and 25p with no crop or 30p using a smaller area of the sensor, and can capture 1080 HD footage at 180 fps using the whole sensor for slow motion effects. In-body 5-axis stabilization helps capture stable video and sharp photographs.

The A9 has dual SD card slots, with Slot 1 supporting the high-speed UHS-II interface. The performance of 132 memory cards was tested in the A9 including UHS-I and UHS-II SD cards. Write speed was calculated for continuous shooting of RAW images. Additional tests were performed to evaluate continuous shooting in RAW+JPEG, RAW and JPEG image modes. Writing to multiple cards using different modes was also evaluated. An analysis has further details about the test results. Fastest and recommended SD cards for the A9 are provided based on the test results.

Sony A9 Camera Details & Settings

The A9 is secured to a tripod. A remote release with timer function is used to provide 1 minute intervals. The subject is a detailed test scene with controlled lighting. Manual focus is set using live view at maximum magnification.

The write speed is calculated during the buffer full condition in continuous shooting. The first frame after the frame rate has been reduced due to the buffer being full until the last frame gives the total time (range: 44.71 - 48.65 seconds). The card access light is not used for this calculation.

Every card was tested at least twice and the results below are an average. The fastest 18 cards were tested 3 to 5 times. Write speed is provided in megabytes per second, where 1 MB = 1,048,576 bytes. The write speed results are for RAW image mode writing to card slot 1. Other image modes (RAW+JPEG and JPEG) have lower write speed.

Sony A9 SD Card Write Speed

+ Show more prices
Memory CardSize
(GB)
Average Write Speed (MB/s)Price
Lexar Professional 2000x UHS-II 64GB64152.0$80.65
Lexar Professional 2000x UHS-II 32GB32150.8$49.99
Lexar Professional 2000x UHS-II Rev E 32GB32149.1$49.99
Lexar Professional 1800x microSD UHS-II 64GB64148.6$124.95
Lexar Professional 2000x UHS-II Rev B 128GB128147.9$188.30
SanDisk Extreme Pro 300MB/s UHS-II 64GB64147.8$119.95
SanDisk Extreme Pro 300MB/s UHS-II 128GB128147.6$249.99
Sony SF-G 300MB/s UHS-II 64GB64147.4$119.98
Sony SF-G 300MB/s UHS-II 128GB128147.1$229.99
Lexar Professional 1800x microSD UHS-II 32GB32146.6$52.25
Sony SF-G 300MB/s UHS-II 32GB32146.3$65.97
SanDisk Extreme Pro 300MB/s UHS-II 32GB32145.6$59.95
SanDisk Extreme Pro 280MB/s UHS-II 32GB32139.5$95.00
Hoodman Steel UHS-II 64GB64139.1$99.99
Transcend Ultimate UHS-II U3 64GB64139.0$101.99
Transcend Ultimate UHS-II U3 32GB32135.1$52.99
Toshiba Exceria Pro UHS-II 32GB32134.0$55.00
Lexar Professional 2000x UHS-II Rev E 64GB64116.6$80.65
Lexar Professional 1800x microSD UHS-II 128GB128105.8$159.99
SanDisk Extreme Pro UHS-II 275MB/s microSDXC 64GB64104.2$99.99
Sony M Series UHS-II 32GB32104.0$28.51
Lexar Professional 1000x UHS-II Rev C 64GB6494.4$41.33
Sony M Series UHS-II 64GB6493.2$55.99
Sony M Series UHS-II 128GB12892.2$99.99
Kingston U3 90/80 MB/s 256GB25678.1$129.95
Patriot EP Series microSDXC 64GB6478.0$31.99
Lexar Professional 1000x UHS-II 32GB3277.9$23.26
PNY Pro Elite microSDXC 64GB6477.8$37.99
Patriot EP PRO microSDXC 64GB6477.7$32.99
SanDisk Extreme Pro 95MB/s 256GB25677.7$122.95
Panasonic Gold 95/90 64GB6477.6$94.99
Kingston U3 (90/80) microSD 64GB6477.5$39.95
Lexar Professional 1000x UHS-II 128GB12877.5$83.95
PNY Pro Elite 64GB6477.5$92.80
SanDisk Extreme Pro 95MB/s 64GB6477.4$46.95
SanDisk Extreme Pro 95MB/s 128GB12877.3$63.49
SanDisk Extreme Pro 95MB/s 32GB3277.2$26.95
SanDisk Extreme Pro 95MB/s microSDXC 64GB6477.2$52.90
SanDisk Extreme Pro 95MB/s U3 32GB3277.0$26.95
SanDisk Extreme Pro 95MB/s U3 V30 256GB25677.0$129.50
SanDisk Extreme Plus 95/90 MB/s U3 V30 microSDXC 64GB6477.0$44.99
SanDisk Extreme Pro 95MB/s microSDHC 32GB3276.8$30.98
SanDisk Extreme Pro 95MB/s U3 V30 128GB12876.7$64.95
Kingston U3 90/80 MB/s 64GB6476.3$34.95
SanDisk Extreme Plus 100MB/s A1 microSDHC 32GB3276.3$29.99
SanDisk Extreme Plus 95/90 MB/s U3 V30 microSDXC 128GB12876.3$89.99
SanDisk Extreme Plus 100MB/s A1 microSDXC 128GB12876.2$99.99
SanDisk Extreme Plus 100MB/s A1 microSDXC 64GB6476.2$49.99
Lexar Professional 1000x UHS-II Rev B 32GB3276.2$23.26
Kingston U3 (90/80) microSD 32GB3276.1$18.95
SanDisk Extreme Plus 95/90 MB/s U3 V30 microSDHC 32GB3275.9$29.95
SanDisk Extreme Pro 95MB/s U3 V30 64GB6475.9$34.94
Kingston U3 90/80 MB/s 32GB3275.8$21.95
SanDisk Extreme Pro 95MB/s U3 V30 32GB3275.7$20.97
Lexar Professional 1000x UHS-II 64GB6475.3$41.33
Samsung PRO Plus 64GB6474.7$54.99
Kingston Class 10 UHS-I 64GB6474.2$30.95
Lexar Professional 1000x UHS-II Rev C 128GB12874.2$83.95
Samsung PRO Select microSDXC 64GB6474.0$49.99
Samsung PRO Plus 32GB3273.5$26.75
Delkin Elite 633x 32GB3273.4$28.95
Samsung EVO Select microSDXC 256GB25673.1$187.66
Delkin Black 32GB3273.1$9223372036854775808.00
Samsung PRO Plus microSDXC 64GB6473.0$52.99
Samsung PRO Plus microSDXC 128GB12872.8$110.95
Lexar Professional 1000x UHS-II 256GB25672.8$167.30
Samsung PRO Select microSDXC 128GB12872.8$590.00
Transcend 633x microSDHC 32GB3271.3$28.99
Transcend 95/85 MB/s U3 32GB3271.0$29.99
Transcend R95 W85 U3 64GB6470.8$60.99
Transcend Ultimate 633x microSD 64GB6470.7$64.49
Samsung PRO U3 64GB6469.8$62.90
Samsung PRO microSDXC 64GB6469.8$69.99
Sony 95MB/s U3 64GB6469.8$47.79
Sony 95MB/s U3 32GB3269.6$29.99
Samsung PRO U3 32GB3269.5$14.95
SanDisk Extreme 100MB/s A1 microSDXC 64GB6465.5$32.90
PNY Elite-X microSDHC 32GB3265.2$17.99
SanDisk Extreme 100MB/s A1 microSDHC 32GB3264.2$19.95
SanDisk Extreme 90MB/s U3 V30 microSDXC 64GB6463.7$29.95
SanDisk Extreme 90MB/s U3 V30 microSDHC 32GB3263.2$18.95
PNY Elite-X microSDXC 64GB6461.3$34.99
SanDisk Extreme Plus 90MB/s U3 V30 32GB3260.8$29.95
SanDisk Extreme Plus 90MB/s U3 V30 64GB6459.9$44.99
SanDisk Extreme 90MB/s U3 V30 256GB25659.5$116.95
SanDisk Extreme 90MB/s U3 V30 128GB12859.5$59.95
Lexar Professional 633x U3 256GB25659.0$109.95
PNY Elite Performance U3 128GB12858.8$64.99
SanDisk Extreme 90MB/s U3 V30 microSDXC 128GB12858.6$69.99
Transcend 95/60 MB/s U3 128GB12858.3$85.99
SanDisk Extreme 100MB/s A1 microSDXC 128GB12858.2$66.97
Transcend 600x 128GB12858.2$81.99
Transcend 95/60 MB/s U3 256GB25658.1$187.99
Transcend 95/60 MB/s U3 64GB6457.9$40.99
Transcend 600x 64GB6457.4$39.97
PNY Elite Performance U1 64GB6457.3$39.99
Lexar Professional 1000x UHS-II microSD 128GB12855.7$122.25
SanDisk Extreme 90MB/s U3 V30 64GB6449.9$28.89
PNY Elite Performance U3 256GB25649.3$129.00
SanDisk Extreme 90MB/s U3 V30 32GB3248.9$18.95
Delkin 1900x UHS-II 32GB3248.8$26.95
Lexar Professional 1000x UHS-II microSD 64GB6448.1$50.59
Lexar Professional 1000x microSD UHS-II 32GB3247.1$24.95
Kingston Class 10 256GB25646.2$106.95
Panasonic MicroP2 UHS-II 32GB3245.5$189.99
Patriot EP Pro 90MB/s 32GB3244.3$54.99
Kingston Ultimate 32GB3244.2$18.95
SanDisk Ultra 80MB/s 32GB3238.5$12.95
Patriot EP Pro 128GB12838.5$59.99
Patriot EP Pro 90MB/s 64GB6437.9$34.99
Transcend 600x 32GB3236.3$20.99
PNY Elite Performance U1 32GB3235.5$22.99
SanDisk Ultra 80MB/s microSD 128GB12835.0$40.80
Lexar Professional 633x microSDXC 200GB20033.3$103.98
PNY Elite microSDXC 64GB6430.5$26.49
SanDisk Ultra 80MB/s 128GB12828.0$44.26
Lexar Professional 633x U1 128GB12826.7$53.76
PNY Elite microSDXC 128GB12826.4$59.99
Lexar Professional 633x U1 64GB6426.2$26.00
Lexar Professional 633x microSDXC 64GB6425.0$27.95
Samsung EVO Select microSDXC 64GB6423.5$39.99
Samsung EVO microSD 32GB3223.0$12.99
Samsung EVO microSDXC 64GB6422.4$24.99
Samsung EVO Select microSDXC 128GB12820.1$79.99
Samsung EVO Plus 128GB microSDXC12820.1$57.19
Lexar Professional 633x microSDXC 128GB12819.5$54.94
SanDisk Ultra 80MB/s 32GB Card 23219.5$12.95
Lexar Professional 633x U1 32GB3219.5$15.99
SanDisk Ultra 80MB/s microSD 64GB6419.1$22.45
SanDisk Ultra 90MB/s microSD 200GB20015.7$74.85
SanDisk Ultra 80MB/s 64GB6415.3$24.85
SanDisk Ultra 80MB/s microSD 32GB3213.7$12.99

Sony A9 Continuous Shooting

Continuous shooting results show a comparison of the number of images taken with different cards. Multiple image modes (RAW+JPEG, RAW, and JPEG) and different image qualities are tested. A detailed test scene is used to produce large file size.

Three cards are compared in the results: The fastest UHS-II card, the fastest UHS-I card and the slowest UHS-I card.

Average write speed is calculated using the buffer full condition based on number of shots, average shot interval and file size. Card access light is not used for write speed calculation.

Time to clear buffer is after one minute of continuous shooting so the buffer is fully saturated. It is the time the last shot is taken until the card access light is extinguished.

Image Type / Card ComparisonShots at full fpsShots in 1 minuteAverage Write SpeedTime to clear buffer
RAW (uncompressed) + JPEG (fine)
Lexar Professional 2000x UHS-II 64GB131245139.0 MB/s44 sec
Kingston 90/80 U3 UHS-I 256GB11417571.9 MB/s1 min 27 sec
SanDisk Ultra (80MB/s) microSD 32GB10912013.7 MB/s7 min 14 sec
RAW (compressed) + JPEG (fine)
Lexar Professional 2000x UHS-II 64GB259403114.53 MB/s1 min 7 sec
Kingston 90/80 U3 UHS-I 256GB23131765.7 MB/s2 min 1 sec
SanDisk Ultra (80MB/s) microSD 32GB21723513.5 MB/s8 min 46 sec
RAW (uncompressed)
Lexar Professional 2000x UHS-II 64GB147293151.9 MB/s32 sec
Kingston 90/80 U3 UHS-I 256GB11719777.7 MB/s1 min 5 sec
SanDisk Ultra (80MB/s) microSD 32GB11012413.7 MB/s6 min 7 sec
RAW (compressed)
Lexar Professional 2000x UHS-II 64GB307520129.0 MB/s43 sec
Kingston 90/80 U3 UHS-I 256GB24937972.1 MB/s1 min 12 sec
SanDisk Ultra (80MB/s) microSD 32GB22224813.7 MB/s6 min 3 sec
JPEG Extra Fine
Lexar Professional 2000x UHS-II 64GB44050843.5 MB/s2 min 55 sec
Kingston 90/80 U3 UHS-I 256GB43850643.5 MB/s2 mins 56 sec
SanDisk Ultra (80MB/s) microSD 32GB40542713.2 MB/s10 min 25 sec
JPEG Fine
Lexar Professional 2000x UHS-II 64GB52864147.8 MB/s1 min 25 sec
Kingston 90/80 U3 UHS-I 256GB51762946.1 MB/s1 min 29 sec
SanDisk Ultra (80MB/s) microSD 32GB43046812.9 MB/s5 min 19 sec
JPEG Standard
Lexar Professional 2000x UHS-II 64GB53264634.7 MB/s1 min 23 sec
Kingston 90/80 U3 UHS-I 256GB52764334.8 MB/s1 min 23 sec
SanDisk Ultra (80MB/s) microSD 32GB44849812.5 MB/s3 min 52 sec

In this comparison it is apparent that large buffer helped even the slowest card achieve a large number of number of shots at full frame rate. The difference is most apparent in buffer clearing time and in the reduced frame rate after the buffer has reached capacity.

Recording to Multiple Cards in the Sony A9

The Sony A9 has two card slots which can be used at the same time. There are two ways to write to both cards cards: simultaneously write the same images to both cards or write different image types to each card. The following tables show results of using each of these modes.

The table below shows the results when writing same images to both cards simultaneously. This mode is used as a backup and provides redundancy in case of card failure.

Recording mode: SimultaneouslyShots at full fpsShots in 1 minuteAverage Write Speed
(per card, limited by slowest)
Time to clear buffer
RAW (uncompressed) + JPEG (fine)
Lexar Professional 2000x UHS-II 64GB
Lexar Professional 2000x UHS-II 32GB
11416662.5 MB/s1 min 38 sec
Lexar Professional 2000x UHS-II 64GB
Kingston 90/80 U3 UHS-I 256GB
11216562.2 MB/s1 min 39 sec
RAW (compressed) + JPEG (fine)
Lexar Professional 2000x UHS-II 64GB
Lexar Professional 2000x UHS-II 32GB
22830257.1 MB/s2 min 8 sec
RAW (uncompressed)
Lexar Professional 2000x UHS-II 64GB
Lexar Professional 2000x UHS-II 32GB
11818767.6 MB/s1 min 13 sec
RAW (compressed)
Lexar Professional 2000x UHS-II 64GB
Lexar Professional 2000x UHS-II 32GB
24636062.8 MB/s1 min 20 sec
JPEG (extra fine)
Lexar Professional 2000x UHS-II 64GB
Lexar Professional 2000x UHS-II 32GB
43950542.4 MB/s2 min 57 sec
JPEG (fine)
Lexar Professional 2000x UHS-II 64GB
Lexar Professional 2000x UHS-II 32GB
49860040.0 MB/s1 min 40 sec
JPEG (standard)
Lexar Professional 2000x UHS-II 64GB
Lexar Professional 2000x UHS-II 32GB
52063332.7 MB/s1 min 27 sec

Writing the the same images to both cards simultaneously reduces write speed. While the A9 is able to write to both cards at the same time, it is slowed down by Slot 2 which does not support UHS-II. The highest write speed was observed recording uncompressed RAW images and reached 67.6 MB/s average which is a little over 10 MB/s slower than the fastest average speed when writing in UHS-I mode. When shooting JPEG images the performance was only slightly slower than writing to one card alone. JPEG performance was limited by processing which reduced write speed.

Recording mode: RAW/JPEG SeparatelyShots at full fpsShots in 1 minuteAverage Write Speed
(both cards combined)
Time to clear buffer
RAW (uncompressed) / JPEG
Slot 1: Lexar Professional 2000x UHS-II 64GB (RAW)
Slot 2: Lexar Professional 2000x UHS-II 32GB (JPEG)
139276170.9 MB/s34.1 sec
JPEG / RAW (uncompressed)
Slot 1: Lexar Professional 2000x UHS-II 32GB (JPEG)
Slot 2: Lexar Professional 2000x UHS-II 64GB (RAW)
11818782.0 MB/s1 min 12.5 sec
RAW (compressed) / JPEG
Slot 1: Lexar Professional 2000x UHS-II 32GB (RAW)
Slot 2: Lexar Professional 2000x UHS-II 64GB (JPEG)
265427130.5 MB/s52.7 sec
RAW (compressed) / JPEG
Slot 1: Lexar Professional 2000x UHS-II 32GB (RAW)
Slot 2: SanDisk Extreme 90MB/s U3 V30 64GB (JPEG)
257415127.1 MB/s54.4 sec

Recording RAW and JPEG separately can provide a slight increase in speed over writing both RAW and JPEG to Slot 1 when using fast cards. Using a somewhat slower card in Slot 2 reduced the speed but even cards that averaged 45-50 MB/s write speed provided performance that was about equal to recording both image types to the fast card. Since JPEG and Slot 2 performance are much slower than the UHS-II speed and faster RAW processing speed, there is little penalty in using a UHS-I card that is slightly slower in Slot 2. As long as the card in Slot 2 can maintain about 50MB/s write speed the penalty is minimal when shooting RAW and JPEG separately.

The default when setting the A9 to "Sort JPEG/RAW" mode is to save the RAW to Slot 2 and JPEG to Slot 1. This is not a favorable configuration when using UHS-II cards because the larger RAW file is written to the slower UHS-I card slot. The solution is to set the default card to Slot 2 by changing "Select Rec. Media" to Slot 2, then RAW images are recorded to Slot 1 and JPEG are saved to Slot 2. The difference between these settings can be seen by comparing the first two rows in the table above.

Analysis

The Sony A9 supports UHS-II in Slot 1 to provide high write speed. Both slots support UHS-I including the fastest UHS-I mode SDR104. Using UHS-II cards provided up to 152 MB/s average write speed, while UHS-I cards averaged up to 78 MB/s.

One important observation is that the A9 has a huge buffer capacity. In continuous shooting RAW compressed images the slowest card captured 222 shots at full frame before it was limited by the card speed, while the fastest card reached 307. Shooting RAW uncompressed images provided slightly lower numbers: 110 images using the slowest card while the fastest card reached 147 images. The difference between them is most apparent when the buffer is full. The frame rate drops and the faster card can sustain a much higher fps with the buffer full. Buffer clearing time is also markedly different between cards. When shooting uncompressed RAW images the slowest card took over 6 minutes to clear the buffer, while the fast card cleared in 31.7 seconds. During the time the buffer is clearing the menus are locked but additional shots can be taken.

In JPEG shooting the camera appears to be processor limited. Card speed had little effect on the number of images taken to full the buffer, while the write speed during buffer-full condition averaged under 50MB/s for the detailed subject scene used for this test. Clearing the buffer took over 10 minutes with a slow card when shooting Extra Fine JPEG due to the large buffer.

Fastest SD Cards for the Sony A9

Fastest UHS-II:
Lexar Professional 2000x UHS-II Card
Lexar Professional 2000x UHS-II


Sony SF-G Series UHS-II

SanDisk Extreme Pro 300MB/s UHS-II
Fastest UHS-I:
Kington 90/80 U3 UHS-I SD Card
Kington 90/80 U3 UHS-I


SanDisk Extreme Pro 95MB/s UHS-I

Samsung Pro Plus UHS-I

The fastest cards for the Sony A9 are UHS-II cards. Lexar Professional 2000x UHS-II cards reached the highest average write speed with the 64GB card measuring 152.0 MB/s. Following close behind were Sony SF-G Series 300MB/s UHS-II cards and SanDisk Extreme Pro 300MB/s UHS-II cards which trailed by only a few MB/s in write speed. In actual use the difference between these UHS-II cards was only six shots in one minute of continuous shooting (range 287-293 shots).

Only Slot 1 supports UHS-II and while UHS-II cards can be used in Slot 2 they only operate in UHS-I mode. In the second slot the write speed is essentially the same as a fast UHS-I card. Some fast UHS-I cards for Slot 2 include Kingston 90/80 U3 UHS-I, SanDisk Extreme Pro 95MB/s, Samsung Pro Plus.

Downloading images from the Sony A9

Sony A9 with USB 2.0 Cable in camera USB Port for transferring images

The A9 provides a USB 2.0 port to connect the camera to a computer to download images. The transfer speed was tested by downloading 50 RAW files (1.2GB) from a Lexar Professional 2000x UHS-II 64GB SDXC card in camera slot 1 to a computer with an SSD drive. The transfer took 59 seconds and averaged 20.3 MB/s. When a separate USB 3.0 card reader that supports UHS-II was tested, the same images downloaded in under 5 seconds at over 240MB/s. See the Card Reader Reviews for card reader tests using a variety of memory cards.