Camera Memory Speed
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Lexar Professional 633x U1 64GB SDXC Memory Card Review

Lexar Professional 633x 64GB UHS-I U1 SDXC Memory Card Front

Introduction

Lexar quietly downgraded the Professional 633x cards from U3 to U1 speed rating. The new 633x U1 cards are rated at the same 95MB/s read speed, but the write speed is quoted at 20MB/s, rather the the 45MB/s speed advertised with the old cards. The UHS Speed Class 1 (U1) specification means the card will sustain at least 10MB/s write speed in continuous recording applications, such as video. The maximum quoted speed at 20MB/s is a maximum rating given by Lexar under ideal conditions.

The new 633x U1 cards are offered in 16, 32, 64 and 128 GB capacities. The 256 and 512GB cards retain the U3 speed rating. This review covers the 633x U1 64GB SDXC card (LSD64GCB1NL633).

Lexar Professional 633x 64GB UHS-I U1 SDXC Memory Card Back

Performance

The 64GB 633x U1 card was tested in various USB 3.0 card readers. The highest sequential read speed reached 96.9 MB/s, which is essentially the same as 96.0 MBs measured with the old U3 card. However when it comes to write speed the new U1 card fell short. Sequential write speed reached 29.5MB/s at best, comapred with the 69.3MB/s of the old card it replaces. The downgrade in speed is accompanied by a lower price. Those looking for performance similar to the old 633x U3 card will have to look at the Lexar Professional 1000x U3 UHS-II card.

Card: Lexar Professional 633x U1 64GB
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 633x U1 64GB
Card Reader Benchmarks
Seq.
Read
1000MB
MB/s
Seq.
Write
1000MB
MB/s
Rand.
Read
512KB
MB/s
Rand.
Write
512KB
MB/s
Rand.
Read
4KB
MB/s
QD1
Rand.
Read
4KB
IOPS
QD1
Rand.
Write
4KB
MB/s
QD1
Rand.
Write
4KB
IOPS
QD1
Rand.
Read
4KB
MB/s
QD32
Rand.
Read
4KB
IOPS
QD32
Rand.
Write
4KB
MB/s
QD32
Rand.
Write
4KB
IOPS
QD32
Lexar LRWM04U-7000 UHS-II Reader96.88428.64588.3349.0906.5531599.70.951232.27.6421865.61.211295.6
Lexar Professional Workflow SR2 UHS-II96.86629.10587.8849.1456.5241592.80.994242.87.6871876.71.238302.2
Transcend Multi-Card Reader RDF995.49028.62587.56711.0276.4881583.90.986240.77.5681847.71.209295.2
SanDisk Extreme Pro UHS-II SD Reader/Writer94.92028.89187.89810.1136.5961610.30.946231.07.6871876.81.252305.7
Transcend Multi-Card Reader RDF8 Black94.83428.57986.9618.9636.2521526.30.617150.77.0811728.71.078263.1
Delkin Dual Slot SD UHS-II and CF Card Reader94.79129.48687.6827.8956.6321619.10.936228.57.6711872.91.252305.8
Lexar Professional Dual Slot UHS-II Card Reader94.72228.72053.08810.6226.1031490.10.620151.36.9081686.50.616150.5
Kingston FCR-HS4 Card Reader94.67128.68687.49611.3416.5501599.20.937228.87.6431866.01.171285.8
Kingston MobileLite G4 UHS-II94.62028.21687.29410.1306.5791606.30.988241.17.6551869.01.234301.2
Delkin Travel Reader94.57728.76585.70510.2076.5261593.40.993242.57.7001879.91.222298.4
Delkin Universal Memory Card Reader94.22928.76986.3319.3085.9761458.90.607148.17.0481720.71.084264.7
Transcend SD Card Reader RDF5 Black94.03428.65186.10411.2345.0891242.40.898219.25.5371351.81.105269.8
Sony MRW-E90 XQD 2.0 / SD UHS-II Card Reader92.61428.81184.2169.3746.1171493.30.927226.37.2321765.71.190290.6
SanDisk ImageMate All-In-One USB 3.092.16628.33977.7368.5264.1591015.50.837204.34.4341082.60.989241.5

The new, downgraded Lexar 633x U1 will be included in upcoming camera tests. The results from the speed tests will be included in the table below when available.

Lexar Professional 633x U1 64GB
Tested in Camera
Write Speed
(MB/s)
Canon 5D Mark IV25.8
Olympus E-M1 II25.6

Cameras tested with this card: Canon 5D Mark IV, Olympus E-M1 II

Lexar Professional series memory cards have a limited lifetime warranty and are made in Korea.

The following table contains information encoded in the SD card.

Lexar Professional 633x U1 64GB SD — Internal Card Information
Serial number (PSN)2484800108
Product Name (PNM)5WCGO
Product Revision0.7
Manufacturer ID (MID)0x000028
OEM ID (OID)BE
Manufacture Date (MDT)06/2016
Total capacity64,155,025,408 bytes

Available sizes and prices

Compare prices on the Lexar Professional 633x U1 card. The lowest prices are highlighted in the table below. Prices are updated daily.

CardSize
GB
Lowest
$ / GB
Prices
AmazonB&H PhotoAdorama
Lexar Professional 633x U116$0.48$9.95$9.95$7.75
Lexar Professional 633x U132$0.40$13.99$12.95$13.95
Lexar Professional 633x U164$0.38$24.54$24.95
Lexar Professional 633x U1128$0.38$48.99$49.95