Lexar Professional 633x U3 128GB SDXC Memory Card Review

Introduction

Lexar offers a wide range of memory cards including several SD card lines. The Lexar Professional 633x SD cards offer fast 95MB/s read speed and high write performance. The cards are an update to the earlier 600x SD cards, and have the new U3 speed designation. The U3 label stands for UHS Speed Class 3 and is displayed on cards that can sustain at least 30MB/s for data-intensive applications such as recording 4K video.

The Lexar 633x 128GB card is rated 45MB/s write speed according to Lexar, the same as the previous 600x card. The 633x cards are available in 16, 32, 64, 128 and 256GB capacities (16GB cards are rated U1 and quoted at 20MB/s maximum write speed). This review is for the 128GB capacity SDXC card (LSD128CBNL633). The card is marked "made in Korea" on the back side.

Performance

In performance tests in USB 3.0 card readers, the 128GB card reached up to 95.5 MB/s sequential read speed, just above the speed quoted by Lexar and close to the 96.0 MB/s measured in the 64GB capacity 633x card tested previously. Sequential write speed measured up to 68.7 MB/s, just slightly below the 69.3 MB/s posted in the 64GB card benchmark. The write speed is comfortably above the 45MB/s write speed quoted by Lexar.

Card: Lexar Professional 633x U3 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

In digital camera tests the write speed measured 58.9 MB/s in the Nikon D500 during continuous shooting of RAW images. Additional in camera write speed averages are shown in the chart below.

Cameras tested with this card: Canon 5D Mark IV, Canon 80D, Fuji X-Pro2, Fuji X-T10, Nikon D500, Olympus PEN-F, Sony A7R II, Sony A6300

The 128GB card performs very similarly to the 64GB capacity 633x card. By offering twice the storage in the same package, it allows additional spave for hours of video recording or thousands of still images. Lexar Professional series memory cards are backed by a lifetime warranty.

The following table contains information encoded in the SD card.

Available sizes and prices

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