Camera Memory Speed
Memory Card Comparison & Performance Tests for Digital Cameras

Lexar Professional 633x U1 128GB SDXC Memory Card Review

Lexar Professional 633x 128GB UHS-I U1 SDXC Memory Card Front

Introduction

Lexar's 633x UHS-I offering has been downgraded from U3 to U1 performance. The write speed that was previously advertised at 45MB/s has been cut to 20MB/s. The card can no longer sustain the 30MB/s continuous write speed required for the UHS-I Class 3 (U3) speed rating, so the card now carries the U1 rating, meaning it can sustain at least 10MB/s write performance for continuous recording.

The Lexar 633x U1 128GB card is offered in 16, 32, 64 and 128GB capacities (256 and 512GB cards retain the U3 speed rating). This test covers the 128GB capacity SDXC card (LSD128GCB1NL633). The card is "made in Korea" as noted on the back side.

Lexar Professional 633x 128GB UHS-I U1 SDXC Memory Card Back

Performance

The 633x U1 128GB SDXC card wast tested in various USB 3.0 card readers using performance benchmark tests. Its sequential read speed reached 96.7 MB/s, nearly as fast as the old card. But the write speed measured 29.6 MB/s in the fastest benchmark, well below the 68.7 MB/s high mark set by the U3-rated card it replaces. While the write speed is above the 20MB/s quoted by Lexar it is quite a downgrade from the previous 633x U3 card.

Card: Lexar Professional 633x U1 128GB
Benchmark: CrystalDiskMark 3.0.3 x64
Program settings: 1000 MB, 5 passes, random test data
Operating system: Windows 10 Pro
Motherboard: Gigabyte GA-Z77X-UD3H
Processor: Intel Core i7-3770K @ 4.40GHz
RAM: 32GB DDR3 1600

Lexar Professional 633x U1 128GB
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
SanDisk Extreme Pro UHS-II USB-C Reader SDDR-40997.81530.82882.18811.4333.958966.41.005245.54.5641114.31.052256.8
SanDisk Extreme Pro SD UHS-II Reader/Writer97.80630.84782.49713.6914.3551063.30.532129.94.4961097.60.992242.2
Sony S1 High Speed UHS-II Reader/Writer97.77829.97382.34912.0373.922957.60.591144.34.4161078.10.38794.6
Delkin Black Rugged Card Reader97.76029.99082.44312.4814.044987.31.013247.34.4481085.91.080263.7
Hama USB 3.0 UHS-II SD Card Reader96.72328.38785.65412.0805.1181249.61.200292.95.8361424.71.226299.2
Lexar Professional Workflow SR2 UHS-II96.71428.59385.57711.8275.3631309.31.166284.75.9561454.11.219297.7
Lexar LRWM04U-7000 UHS-II Reader96.70528.63685.39211.5795.3231299.51.202293.45.9121443.41.238302.4
Hama USB Type-C 3.1 UHS-II SD Card Reader96.61628.76684.31311.6205.4191323.00.855208.85.9261446.70.476116.1
Lexar Professional Dual Slot UHS-II Card Reader95.04028.85285.42011.4355.4051319.51.140278.35.9001440.31.215296.6
Delkin Multi-Card CFast SD UHS-II microSD Reader94.98828.52985.36311.5815.4441329.11.211295.75.9711457.81.240302.8
SanDisk Extreme Pro UHS-II SD Reader/Writer94.94528.83385.75211.6805.3441304.71.190290.65.8801435.51.217297.2
Kingston MobileLite G4 UHS-II94.89428.96085.73811.3625.3461305.11.201293.35.9371449.61.230300.3
SanDisk ImageMate Pro Multi-Card Reader/Writer94.88530.07380.93811.5453.948963.90.998243.64.5371107.61.061259.1
Transcend Multi-Card Reader RDF8 Black94.88528.63984.88411.9455.0241226.70.527128.73.527861.10.509124.4
Delkin Dual Slot SD UHS-II and CF Card Reader94.77429.00585.76611.8165.3971317.71.200292.95.9381449.81.240302.8
Kingston FCR-HS4 Card Reader94.71428.60085.39211.5145.3451304.91.197292.25.9271447.01.231300.5
Delkin Travel Reader94.58628.73783.56611.6235.2951292.71.215296.65.9311448.01.249305.0
Transcend Multi-Card Reader RDF994.36428.65185.42011.9125.3891315.61.166284.65.9001440.61.230300.2
Delkin Universal Memory Card Reader94.22929.62584.88411.5524.9731214.11.104269.65.6871388.41.190290.6
Transcend SD Card Reader RDF5 Black93.90828.57983.92811.4984.2161029.21.038253.44.5981122.51.095267.4
Sony MRW-E90 XQD 2.0 / SD UHS-II Card Reader93.10728.97682.52412.0805.2301276.81.125274.75.7131394.71.180288.2
SanDisk ImageMate All-In-One USB 3.091.77128.45375.98410.8523.635887.40.995242.93.798927.41.004245.2
DriverGenius USB 3.1(G1) / 3.0 UHS-II SD Card Reader70.89328.05864.80113.4594.7601162.10.603147.15.4121321.30.668163.1

The 633x U1 card will be included in digital camera speed tests. When the results are available they will be added to the chart below.

Lexar Professional 633x U1 128GB
Tested in Camera
Write Speed
(MB/s)
Canon EOS R31.9
Fuji X-T328.9
Sony A926.7
Canon EOS M526.5
Canon 5D Mark IV26.4
Nikon D750025.9
Canon 77D25.5
Nikon D560025.3
Nikon Coolpix P100021.7
Olympus E-M1 II21.5
Panasonic GH521.3
Canon Rebel T7i19.9

Cameras tested with this card: Canon EOS R, Canon 5D Mark IV, Canon 77D, Canon EOS M5, Canon Rebel T7i, Fuji X-T3, Nikon D7500, Nikon D5600, Nikon Coolpix P1000, Olympus E-M1 II, Panasonic GH5, Sony A9

Lexar Professional series memory cards are backed by a lifetime warranty.

The following table contains information encoded in the SD card.

Lexar Professional 633x U1 128GB SD — Internal Card Information
Serial number (PSN)1411187524
Product Name (PNM)5WCGO
Product Revision0.8
Manufacturer ID (MID)0x000028
OEM ID (OID)BE
Manufacture Date (MDT)06/2016
Total capacity128,042,663,936 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$0.81$13.00Check priceCheck price
Lexar Professional 633x U132$0.31$9.99Check priceCheck price
Lexar Professional 633x U164$0.20$12.99Check priceCheck price
Lexar Professional 633x U1128$0.14$17.95Check priceCheck price