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Lexar Professional Dual Slot UHS-II SD/CF Reader Review

Lexar Professional Workflow Dual Slot Card Reader LRW400CRBNA


The Lexar Professional Dual-Slot Reader LRW400U is an update to the Dual-Slot LRW300U CF and SD card reader. It shares the same pop-up case design and adds support for UHS-II SD cards. The reader also supports standard SD, SDHC and SDXC cards including UHS-I and CompactFlash cards up to UDMA 7.

The most notable change is the addition of UHS-II support which requires an extra row of pins to in the reader to interface additional contacts of UHS-II SD cards. As a result SD cards insert slightly over 3/4 inches (20mm) into the reader. Compact Flash cards insert to a similar depth. The fit in both slots is precise and cards insert smoothly and seat with a firm and positive feel. A blue LED illuminates when a card is present and flashes to indicate when a card is in use. The light on the reader was not as bright as the previous model and appeared to be mounted below the window, reducing its visibility.

Lexar Professional Dual Slot Card Reader LRW400CRBNA Closed

Externally, the Dual Slot LRW400U is the same as its predecessor. A translucent outer case surrounds the reader and serves to protect the card slots when the reader is transported. The top portion of the reader is glossy black plastic. The reader is opened by pressing tabs on the sides of the case. Once pressed, the reader opens quickly and closing is as simple as pushing the reader closed until it clicks.

Lexar Professional Workflow Dual Slot Card Reader LRW400CRBNA Bottom

The bottom of the reader is covered in a white rubber to prevent the reader from slipping. A label on the bottom shows the part number LRW400U revision A, the serial number and indicates the reader is made in China. The back of the reader has a micro USB 3 port. A 40-inch USB 3.0 cable is included with the reader. The reader can use a USB 3.0 connection and is backwards compatible with USB 2.0.

Lexar Professional Workflow Dual Slot Card Reader Box LRW400CRBNA Packaging


The Lexar Dual-Slot Reader was tested with a variery of CompactFlash and Secure Digital cards. The Lexar Professional 2000x UHS-II 64GB SDXC measured 268MB/s sequential read speed and 250MB/s write speed. Using UDMA7 CompactFlash cards such as the Lexar Professional 1066x 128GB, the reader reached over 158MB/s read and 155MB/s write speeds. Results using various cards can be viewed in the table below. With UHS-II SD cards the Dual Slot LRW400U was not quite as fast as the Lexar SR2 UHS-II SD card reader. The CF card write speed improved over the previous Dual Slot reader, up from 139MB/s to over 155MB/s with the new reader.

In the Dual Slot reader both cards can be accessed at the same time, although performance was slightly compromised when reading and/or writing two fast card simultaneously. In the best case the sum of concurrent transfers was just over 200MB/s. Copying from one card to the other measured about 90MB/s when using fast UHS-II SD and UDMA 7 CF cards.

Reader: Lexar Professional Dual Slot UHS-II Card Reader
Benchmark: CrystalDiskMark 3.0.3 x64
Program settings: 1000 MB, 5 passes, random test data
Operating system: Windows 8.1 Pro
Motherboard: Gigabyte GA-Z77X-UD3H
Processor: Intel Core i7-3770K @ 4.40GHz
RAM: 32GB DDR3 1600

Lexar Professional Dual Slot UHS-II Card Reader
Card Benchmarks
Lexar Professional 2000x UHS-II 64GBSD268.762251.517
Transcend Ultimate UHS-II U3 64GBSD266.576181.855
Lexar Professional 2000x UHS-II 32GBSD266.035250.406
Transcend Ultimate UHS-II U3 32GBSD265.328186.264
Toshiba Exceria Pro UHS-II 32GBSD255.252221.312
Lexar Professional 1800x microSD UHS-II 32GBmicroSD243.261204.960
Delkin 1900x UHS-II 32GBSD242.10951.128
Sony M Series UHS-II 64GBSD240.74899.062
SanDisk Extreme Pro 280MB/s UHS-II 32GBSD240.444201.166
SanDisk Extreme Pro UHS-II 275MB/s microSDXC 64GBmicroSD239.592105.459
Panasonic MicroP2 UHS-II 32GBSD238.06949.155
Lexar Professional 1066x 64GBCF159.966152.056
Lexar Professional 800x 64GBCF159.84475.901
Lexar Professional 1066x 32GBCF159.698150.983
SanDisk Extreme Pro 160MB/s 32GBCF159.358147.479
SanDisk Extreme Pro 160MB/s 256GBCF159.213130.876
Komputerbay 1066x 128GBCF158.996151.092
Transcend 1000x 32GBCF158.611131.598
PixelFlash SuperSport 1000X-PRO 128GBCF158.563139.253
Lexar Professional 800x 32GBCF158.39546.075
Lexar Professional 1066x 128GBCF158.276155.644
Toshiba Exceria 1000x 32GBCF158.085123.116
Transcend 1000x 128GBCF158.085148.776
SanDisk Extreme Pro 160MB/s 64GBCF157.633151.990
Toshiba Exceria 1000x 64GBCF157.067118.283
Transcend 800x 32GBCF156.78540.436
Toshiba Exceria Pro 1066x 32GBCF156.178146.306
SanDisk Extreme Pro 160MB/s 128GBCF156.085141.089
Lexar Professional 1000x UHS-II 32GBSD154.08988.027
Lexar Professional 1000x UHS-II 64GBSD153.05483.832
Lexar Professional 1000x UHS-II 128GBSD151.59486.104
Toshiba Exceria Pro 1066x 64GBCF151.441147.999
Lexar Professional 1000x microSD UHS-II 32GBmicroSD151.35352.471
Kingston Ultimate 600x 32GBCF128.628110.284
SanDisk Extreme 120MB/s 32GB Card 2CF124.07783.792
SanDisk Extreme 120MB/s 32GBCF122.44068.768
SanDisk Extreme 90MB/s U3 32GBSD97.99849.452
SanDisk Extreme 90MB/s U3 V30 256GBSD97.72464.823
SanDisk Extreme Pro 95MB/s microSDXC 64GBmicroSD97.70691.451
SanDisk Extreme 90MB/s U3 V30 microSDXC 128GBmicroSD97.64263.751
SanDisk Ultra 80MB/s 32GB Card 2SD97.64220.666
SanDisk Extreme Pro 95MB/s 64GBSD97.62491.443
SanDisk Extreme Pro 95MB/s microSDHC 32GBmicroSD97.57891.109
SanDisk Ultra 80MB/s 128GBSD97.55139.171
SanDisk Extreme Pro 95MB/s 128GBSD97.54291.022
SanDisk Extreme Pro 95MB/s 32GBSD97.51589.829
SanDisk Extreme Plus 95/90 MB/s microSD 32GBmicroSD97.47891.331
SanDisk Extreme 90MB/s U3 64GBSD97.46049.484
SanDisk Extreme Plus 80MB/s microSD 32GBmicroSD97.42465.097
SanDisk Extreme Plus 95/90 MB/s microSD 64GBmicroSD97.30791.046
SanDisk Extreme Pro 95MB/s U3 32GBSD97.29890.762
SanDisk Extreme Pro 95MB/s 256GBSD97.13589.952
SanDisk Extreme 90MB/s microSDHC 32GBmicroSD97.10848.266
SanDisk Ultra 80MB/s microSD 128GBmicroSD96.97452.671
SanDisk Ultra 80MB/s microSD 64GBmicroSD96.96521.393
Kingston U3 90/80 MB/s 64GBSD96.79584.809
SanDisk Extreme Plus 90MB/s 32GBSD96.68871.968
Kingston U3 90/80 MB/s 32GBSD96.67989.028
Toshiba Exceria UHS-I Class 3 64GBSD96.67060.759
SanDisk Extreme Plus 80MB/s 32GBSD96.61661.605
Toshiba Exceria Type 2 32GBSD96.60765.561
Panasonic Gold 95/90 64GBSD96.54587.069
Kingston Class 10 UHS-I 64GBSD96.54580.772
Toshiba Exceria UHS-I Class 3 32GBSD96.45661.601
PNY Pro Elite microSDXC 64GBmicroSD96.27987.019
Toshiba Exceria Type 1 32GBSD96.23586.903
Patriot EP Series microSDXC 64GBmicroSD96.21781.990
Patriot EP PRO microSDXC 64GBmicroSD96.17382.306
Delkin Black 32GBSD96.11180.338
Kingston U3 (90/80) microSD 64GBmicroSD96.10383.154
Samsung PRO Plus 64GBSD96.04188.420
Kingston U3 (90/80) microSD 32GBmicroSD96.00686.616
Samsung PRO Plus 32GBSD95.95387.740
Delkin Elite 633x 32GBSD95.86581.990
Samsung PRO U3 64GBSD95.85778.959
Samsung PRO microSDXC 64GBmicroSD95.84878.545
Samsung EVO Select microSDXC 64GBmicroSD95.83025.454
Samsung PRO Plus microSDXC 64GBmicroSD95.82287.272
PNY Pro Elite 64GBSD95.76086.147
Samsung PRO U3 32GBSD95.70879.383
Patriot EP Pro 90MB/s 32GBSD95.57747.660
Samsung PRO Select microSDXC 64GBmicroSD95.54286.882
Samsung EVO Select microSDXC 256GBmicroSD95.53489.309
PNY Elite Performance U1 32GBSD95.51638.222
Transcend 95/85 MB/s U3 32GBSD95.23988.525
Transcend 600x 64GBSD95.23065.948
Lexar Professional 600x 64GBSD95.21366.742
SanDisk Extreme Plus 80MB/s 64GBSD95.20460.942
PNY Elite Performance U3 128GBSD95.19567.541
Transcend 633x microSDHC 32GBmicroSD95.14388.570
Transcend 95/60 MB/s U3 64GBSD95.14367.324
Lexar Professional 633x U3 256GBSD95.13568.836
Lexar Professional 633x U1 128GBSD95.04028.852
Transcend 95/60 MB/s U3 128GBSD95.04066.712
Sony 94MB/s 32GBSD94.99765.271
PNY Elite Performance U3 256GBSD94.99756.321
Transcend 600x 128GBSD94.98069.323
Transcend R95 W85 U3 64GBSD94.95481.792
Gobe Magic 104MB/s 32GBSD94.92888.376
Transcend 95/60 MB/s U3 256GBSD94.92068.342
Sony 95MB/s U3 32GBSD94.91186.975
Transcend 600x 32GBSD94.87739.126
PNY Turbo Performance U3 microSD 32GBmicroSD94.86856.698
Panasonic Gold Series 32GBSD94.85943.765
PNY Elite Performance U1 64GBSD94.85964.964
Lexar Professional 633x U3 128GBSD94.84268.454
Patriot EP Pro 128GBSD94.83442.613
Gobe Magic 104MB/s 64GBSD94.82587.178
PNY Elite microSDXC 128GBmicroSD94.81727.689
Samsung PRO 32GBSD94.79981.323
Transcend Ultimate 633x microSD 64GBmicroSD94.78287.280
Patriot EP Pro 90MB/s 64GBSD94.78241.470
Sony 95MB/s U3 64GBSD94.76586.338
PNY Elite-X microSDHC 32GBmicroSD94.74876.410
Lexar Professional 633x microSDXC 64GBmicroSD94.72228.029
Lexar Professional 633x U1 64GBSD94.72228.720
PNY Turbo Performance microSDXC 64GBmicroSD94.71458.760
Kingston Ultimate 32GBSD94.71446.981
Lexar Professional 633x U3 32GBSD94.68848.408
Lexar Professional 633x U1 32GBSD94.54322.286
PNY Elite microSDXC 64GBmicroSD94.53432.154
Lexar Professional 633x U3 64GBSD94.48367.772
PNY Elite-X microSDXC 64GBmicroSD94.48372.717
SanDisk Extreme Plus 90MB/s 64GBSD94.44971.810
Lexar Professional 600x 32GBSD94.41548.208
Samsung PRO 64GBSD94.37382.332
SanDisk Ultra 80MB/s 32GBSD93.62342.806
Samsung PRO Select microSDXC 128GBmicroSD92.75383.893
Samsung PRO Plus microSDXC 128GBmicroSD92.69683.866
SanDisk Extreme 90MB/s microSDXC 64GBmicroSD92.32943.355
Lexar Professional 633x microSDXC 200GBmicroSD91.10936.314
SanDisk Ultra 90MB/s microSD 200GBmicroSD90.58221.038
SanDisk Extreme 90MB/s U3 128GBSD85.66178.141
SanDisk Extreme 80MB/s 128GBSD84.72779.257
Samsung EVO Plus 128GB microSDXCmicroSD83.98721.917
Lexar Professional 633x microSDXC 128GBmicroSD83.70522.229
SanDisk Extreme 80MB/s 256GBSD82.80078.787
SanDisk Ultra 80MB/s microSD 32GBmicroSD82.45517.544
Samsung EVO Select microSDXC 128GBmicroSD81.65223.254
SanDisk Ultra 80MB/s 64GBSD81.25315.056
SanDisk Extreme 60MB/s 32GBSD74.94654.793
SanDisk Extreme U3 microSD 32GBmicroSD74.55754.084
Lexar Professional 400x 32GBSD71.54643.362
SanDisk Extreme 60MB/s 64GBSD70.91252.410
SanDisk Extreme U3 microSD 64GBmicroSD68.66055.577
Delkin Cinema 1050X 32GB Card 2CF66.349133.526
SanDisk Ultra 50MB/s 32GBCF53.25730.694
SanDisk Extreme 45MB/s 32GBSD47.65844.616
SanDisk Ultra microSD 64GBmicroSD47.60415.361
SanDisk Ultra 40MB/s 64GBSD47.55415.651
Samsung EVO 64GBSD47.54623.641
SanDisk Ultra microSD 32GBmicroSD47.54214.637
Samsung EVO microSD 32GBmicroSD47.46624.563
Samsung EVO microSDXC 64GBmicroSD47.41323.468
Samsung EVO 32GBSD47.37028.720
SanDisk Ultra 40MB/s 32GB Card 2SD47.23519.908
Toshiba NFC 16GBSD37.86813.135

Compatible operating systems include Mac OS X 10.6+ and Windows 8/7. The Dual-Slot Reader is backed by a five-year warranty. The product code for North America is LRW400CRBNA.

Compare prices on the Lexar Professional Dual Slot UHS-II. The lowest prices are highlighted in the table below.

Card ReaderConnectionModel NumberPrices
AmazonB&H PhotoAdorama
Lexar Professional Dual Slot UHS-II Card ReaderUSB 3.0LRW400CRBNA$19.95$19.95$32.09