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SanDisk Extreme Pro UHS-II SD Reader Writer USB 3.0 SDDR-329

SanDisk Extreme Pro UHS-II SD Reader Writer USB 3.0 SDDR-329


The SanDisk Extreme Pro UHS-II SD Reader/Writer (SDDR-329) is a high-speed USB 3.0 SD card reader. It is compatible with SD/SDHC/SDXC cards including UHS-I and UHS-II. The reader has a second row of pins to support the new UHS-II standard.

SanDisk advertises this reader with 500 MB/s USB 3.0 performance, which is technically true of USB 3.0, but UHS-II operates at 312 MB/s maximum bus speed. Actual read and write performance of UHS-II cards is typically closer to 250 MB/s.

The exterior of the Extreme Pro UHS-II Reader is plastic with a faux brushed metal appearance. The ends of the reader and the slider are high gloss. The plastic is rigid and thick enough to provide durability. The reader is deceiptively lightweight but feels solid. Unlike most card readers, this one has no card access light.

SanDisk Extreme Pro UHS-II SD Reader Writer USB 3.0 Extended

The USB plug is extended and retracted by a slider on the top side of the reader. It locks in both open and closed positions. The USB plug must be retracted to insert a card. This means it is not possible to insert or remove a card unless the reader is unplugged from the USB port. This can be a minor or major annoyance depending how often one changes cards. (Althrough not recommended, it is possible to put a card in the slot while the reader is plugged in, but the card must be pushed in about 5mm past the opening, which could be done using another card. Removal could be accomplished by using a piece of tape as a tail on the card.)

The slider operation is quirky. It is unlocked by pressing down on the end of the slider button toward the USB plug. This makes extending the plug counterintuive because the ridge on the center of the slider means the opposite end will be used to push. Depending on how the sider is pressed it may emit clicking noises or no sound at all. It requires very little force to lock or unlock, and latches into position when moved fully to either end. On first use it does not instill much confidence, but it works reasonably well after understanding its operation.

The case measures 2.25 x 1.375 x 0.5 inches (57 x 35 x 13mm) not including the USB plug. This makes it rather large for a compact card reader. The reader overhangs the USB plug by 11mm on each side, 1mm on the bottom and 8mm on the top. Its size may cause interference with adjacents ports.


UHS-II is capable of delivering amazing throughput, and the SanDisk Extreme Pro UHS-II reader does not disappoint. We tested the reader using both UHS-I and UHS-II cards. The fastest read and write speeds were seen using the Toshiba Exceria Pro UHS-II card: 248.6 MB/s sequential read and 215.9 MB/s sequential write.

The Extreme Pro UHS-II Reader also performed well using UHS-I cards. A majority of the cards performed at or slightly above specified speed. The SanDisk Extreme Pro 95MB/s UHS-I card achieved the highest UHS-I read speed we have seen on any card reader: 98.495 MB/s.

Reader: SanDisk Extreme Pro UHS-II SD Reader/Writer
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

SanDisk Extreme Pro UHS-II SD Reader/Writer
Card Benchmarks
Toshiba Exceria Pro UHS-II 32GB248.625215.890
Lexar Professional 2000x UHS-II 32GB243.883230.380
Lexar Professional 2000x UHS-II 64GB241.246227.556
Transcend Ultimate UHS-II U3 64GB240.334172.890
Panasonic MicroP2 UHS-II 32GB240.19649.298
SanDisk Extreme Pro 280MB/s UHS-II 32GB240.086202.957
Sony M Series UHS-II 64GB238.20499.137
Lexar Professional 1800x microSD UHS-II 32GB238.096201.127
Delkin 1900x UHS-II 32GB236.59250.887
Transcend Ultimate UHS-II U3 32GB236.405179.228
SanDisk Extreme Pro UHS-II 275MB/s microSDXC 64GB235.212106.185
Lexar Professional 1000x UHS-II 32GB154.04487.924
Lexar Professional 1000x UHS-II 64GB153.16683.472
Lexar Professional 1000x UHS-II 128GB152.07886.175
Lexar Professional 1000x microSD UHS-II 32GB151.74852.865
SanDisk Extreme Plus 80MB/s microSD 32GB98.54165.389
SanDisk Extreme Pro 95MB/s 64GB98.51392.483
SanDisk Extreme Pro 95MB/s 32GB98.49590.762
SanDisk Extreme Plus 80MB/s 32GB98.44959.406
SanDisk Ultra 80MB/s microSD 128GB98.21878.334
SanDisk Extreme 90MB/s U3 V30 256GB97.89764.947
SanDisk Extreme Pro 95MB/s U3 32GB97.86191.731
SanDisk Extreme 90MB/s U3 V30 microSDXC 128GB97.77863.600
SanDisk Extreme 90MB/s U3 64GB97.69649.721
SanDisk Extreme Pro 95MB/s 128GB97.67891.475
SanDisk Extreme Plus 95/90 MB/s microSD 32GB97.63391.236
SanDisk Extreme Pro 95MB/s microSDXC 64GB97.57891.475
SanDisk Extreme Pro 95MB/s microSDHC 32GB97.55191.308
SanDisk Ultra 80MB/s microSD 64GB97.55120.896
Kingston Class 10 UHS-I 64GB97.49771.220
Kingston U3 90/80 MB/s 64GB97.48885.717
SanDisk Extreme 90MB/s U3 32GB97.47848.965
Kingston U3 90/80 MB/s 32GB97.42490.778
SanDisk Extreme Plus 95/90 MB/s microSD 64GB97.41591.157
SanDisk Extreme 90MB/s microSDHC 32GB97.39748.330
Toshiba Exceria Type 1 32GB97.09987.872
Toshiba Exceria Type 2 32GB97.09065.068
SanDisk Extreme Pro 95MB/s 256GB97.03690.324
Toshiba Exceria UHS-I Class 3 64GB96.93860.025
Patriot EP PRO microSDXC 64GB96.90287.265
PNY Pro Elite microSDXC 64GB96.86687.156
SanDisk Extreme Plus 90MB/s 32GB96.75071.830
Panasonic Gold 95/90 64GB96.69687.280
Toshiba Exceria UHS-I Class 3 32GB96.67960.868
Kingston U3 (90/80) microSD 64GB96.57284.284
Patriot EP Series microSDXC 64GB96.55483.148
Samsung PRO Plus microSDXC 64GB96.41288.101
PNY Pro Elite 64GB96.38586.566
Samsung PRO Plus 32GB96.29788.182
Samsung EVO Select microSDXC 256GB96.12987.323
Samsung PRO Plus 64GB96.08588.487
Delkin Elite 633x 32GB96.05081.709
Samsung PRO U3 64GB96.05079.263
Delkin Black 32GB95.90981.443
Samsung PRO U3 32GB95.86579.867
Transcend R95 W85 U3 64GB95.85788.832
Samsung PRO microSDXC 64GB95.85779.126
Transcend 95/60 MB/s U3 64GB95.83966.194
PNY Elite Performance U1 64GB95.83066.357
Transcend 600x 32GB95.78739.062
PNY Elite Performance U1 32GB95.77838.241
Kingston Ultimate 32GB95.74347.064
Transcend 95/85 MB/s U3 32GB95.73488.810
Lexar Professional 600x 64GB95.72567.878
Sony 95MB/s U3 64GB95.71788.376
Sony 94MB/s 32GB95.70866.089
Patriot EP Pro 90MB/s 64GB95.69039.714
Patriot EP Pro 90MB/s 32GB95.66447.458
Lexar Professional 600x 32GB95.64748.570
Samsung PRO Select microSDXC 64GB95.59486.903
Samsung EVO Select microSDXC 64GB95.54225.330
Sony 95MB/s U3 32GB95.52588.271
Transcend 633x microSDHC 32GB95.38686.409
Transcend 95/60 MB/s U3 128GB95.33468.276
Samsung PRO 32GB95.33481.824
Lexar Professional 633x microSDXC 64GB95.28228.200
PNY Elite Performance U3 256GB95.25655.389
PNY Elite microSDXC 64GB95.23032.617
Lexar Professional 633x U3 256GB95.16168.858
Transcend 600x 128GB95.12669.135
Lexar Professional 633x U3 128GB95.11868.530
Panasonic Gold Series 32GB95.11843.515
Transcend 95/60 MB/s U3 256GB95.05768.449
Samsung PRO 64GB95.04983.565
PNY Turbo Performance U3 microSD 32GB95.04057.579
Transcend 600x 64GB95.03167.480
PNY Elite microSDXC 128GB95.03127.682
Gobe Magic 104MB/s 32GB94.96387.806
PNY Elite-X microSDXC 64GB94.94573.734
Lexar Professional 633x U1 128GB94.94528.833
Gobe Magic 104MB/s 64GB94.93787.185
PNY Elite-X microSDHC 32GB94.93776.382
Lexar Professional 633x U1 64GB94.92028.891
Patriot EP Pro 128GB94.91142.511
PNY Elite Performance U3 128GB94.88568.463
Lexar Professional 633x U1 32GB94.87722.255
PNY Turbo Performance microSDXC 64GB94.81759.101
SanDisk Extreme Plus 80MB/s 64GB94.40760.601
Transcend Ultimate 633x microSD 64GB94.39886.968
SanDisk Extreme Plus 90MB/s 64GB94.07669.553
Lexar Professional 633x U3 64GB93.97568.981
Samsung PRO Select microSDXC 128GB93.53184.270
Lexar Professional 633x U3 32GB93.50648.563
Samsung PRO Plus microSDXC 128GB93.00883.960
SanDisk Extreme 90MB/s microSDXC 64GB92.52443.403
Lexar Professional 633x microSDXC 200GB90.69236.777
SanDisk Ultra 90MB/s microSD 200GB90.53521.046
Samsung EVO Plus 128GB microSDXC87.60822.535
SanDisk Extreme 90MB/s U3 128GB85.46578.048
SanDisk Extreme 80MB/s 128GB84.48179.504
Lexar Professional 633x microSDXC 128GB83.39922.688
SanDisk Ultra 80MB/s microSD 32GB82.52618.178
Samsung EVO Select microSDXC 128GB82.42223.052
SanDisk Extreme 80MB/s 256GB81.50678.876
SanDisk Extreme 60MB/s 32GB75.34554.776
SanDisk Extreme U3 microSD 32GB74.65854.140
Lexar Professional 400x 32GB71.85043.378
SanDisk Extreme 60MB/s 64GB70.77352.658
SanDisk Extreme U3 microSD 64GB68.33355.316
SanDisk Ultra 40MB/s 64GB47.73215.867
SanDisk Ultra microSD 32GB47.73015.127
SanDisk Ultra microSD 64GB47.73015.965
SanDisk Ultra 40MB/s 32GB Card 147.72545.032
SanDisk Extreme 45MB/s 32GB47.72344.845
Samsung EVO microSD 32GB47.62624.505
Samsung EVO 64GB47.56323.691
Samsung EVO microSDXC 64GB47.53123.587
Samsung EVO 32GB47.40820.165
SanDisk Ultra 40MB/s 32GB Card 347.22719.730
SanDisk Ultra 40MB/s 32GB Card 247.22319.925
Toshiba NFC 16GB37.86813.066
Toshiba FlashAir II 32GB19.10212.962


The performance of the SanDisk Extreme Pro UHS-II Reader is undeniable. It is one of the few readers that supports UHS-II. However its quirky slider operation and inability to change cards without unplugging the reader make it more difficult to use than other readers. One should also consider the Kingston MobileLite G4 reader which also UHS-II compatible.

Compatibility includes Mac OS 10.3x and up, Windows 8 and Windows 7. It is compatible with USB 3.0 and USB 2.0 devices. Two year warranty. Made in China.

Compare prices on the SanDisk Extreme Pro UHS-II SD Reader. The lowest prices are highlighted in the table below.

Card ReaderConnectionModel NumberPrices
AmazonB&H PhotoAdorama
SanDisk Extreme Pro UHS-II SD Reader/WriterUSB 3.0SDDR-329-A46$28.99$36.00$37.49