We are continuing the product range from Lexar with their 633x high speed class microSD memory cards built for ultimate performance.

First about Lexar:


Lexar Media, Inc. is an American manufacturer of digital media products based in Fremont, CA. Products manufactured by Lexar include SD cards, Memory Sticks, keydrives, CompactFlash cards and card readers.

Once a division of Cirrus Logic, Lexar leveraged its parent company’s experience in building ATA controllers in developing its own flash controllers.
Lexar was acquired by Micron Technology in 2006, and subsequently merged with Crucial Technology under the name Lexar Media, a subsidiary of Micron. In September 2007, Lexar extended its agreement with Eastman Kodak Company to develop and market Kodak-branded flash memory products worldwide.


Price when reviewed: £19.99 – via Amazon.co.uk

LEXAR High-Performance 633x 64 GB MicroSDXC UHS-I Card with SD adapter


Presentation and Specification



– Premium memory solution for sports camcorders, tablets, and smartphones
– Quickly captures, stores, plays back, and transfers media files, including 1080p full-HD, 3D, and 4K video
– Leverages UHS-I technology for a transfer speed up to 633x (95MB/s)
– Stores more than 36 hours of HD video; 67,600 photos; or 58,100 songs
– Includes high-speed, Class 10 card and SD adapter (16GB-128GB) or USB 3.0 reader (200GB-256GB)
– Limited lifetime warranty for card and one-year limited warranty for USB 3.0 reader or adapter

Via Lexar’s website, where we also learn that it carris the Part Nr. #LSDMI64GBBNL633A




Comes protected in standard memory card envelope with a transparent cover so you can clearly see the products inside. On the front we have all the crucial (no pun intended) information like compatibility (4k HD camera’s, drones, smartphones, tablets etc), the speed class and standard (Class 10 UHS-I microSDXC – which is the maximum for this generation) and the available capacity (64 GB) and the read speeds which are up to 95 MB/s.


On the back we see besides the multilingual presentation, where it was built – Korea.


Inside, we have the memory card nested in its own case, along with an SD card adapter.


The Lexar 633x microSDXC card has a dual tone color paint job – on the black section we have the brand, the 633x category and the 10 circled which referrers to the Class 10 speed category.
Then on the blue part we have the capacity of 64 GB and the speed protocols and format – MicroSDXC U1.
Also this is the included USB 3.0 adapter included with the bigger capacity memory cards, as a size reference as well.


And finally on the back of the card, we have again the built origin and the serial/part number.



Testing methodology


Synthetic tests and some real life file transfers on both our test computer and smartphone. Then we will test it against a 128 GB microSDXC from another brand with the same speed protocols.

Hardware used.


– CPU: Intel i7 4790k @ stock 4.0 Ghz w/ 4.4 Turbo Boost – 88 W TDP
– CPU Cooler: Cryorig C7
– SSD: Samsung M.2 950 Pro 512 GB MLC NVMe
– Memory Modules: 16 GB (2x 8 GB) DDR3 Crucial Ballistix Tactical Tracers 1600 Mhz CL8 LED
– Video card: MSI GTX 980Ti 6G Twin Frozr V Gaming
– Case: Thermaltake V1 Core mITX
– Fans: 1x Thermaltake 200 mm
– PSU: Corsair SF600 SFX 600W


– Samsung Galaxy Note 4


– Samsung EVO 128 GB MicroSDXC UHS-1 Grade 1 Class 10

Software used.

– Windows 10 Pro x64 Build 1511.10586
– Crystal Disk Mark v3.0.2
– A1 SD Bench (Android)




First let’s do a synthetic test on the PC with a Lexar USB 3.0 microSD card reader. Used for both cards.

Samsung 128 GB EVO


Lexar 64 GB 633x


So Lexar wins in both read and write tests on all accounts. It promised 95 MB/s read theoretical read seed. It delivers just that.

Then let’s see how it performs on a smartphone.

First the Samsumg 128 GB EVO


Then the Lexar 64 Gb 633x


Almost double in write and read for the Lexar one !

And finally a big file transfer (~ 5 GB .mkv movie ) from the PC to the cards.

Samsung 128 GB EVO


Lexar 64 GB 633x


Lexar is ~ 37 % faster !




So in all tests the Lexar is a clear winner compared to a bigger card with the same speed protocols. Flawless victory.

The good:

+ High performance as quoted
+ High quality product
+ Easily recognizable design
+ Good price
+ Included USB 3.0 card adapter/ SD reader (depending on model)
+ Up in the lead regarding the max capacity microSD offering on the market

The Bad:

– Maybe include the Lexar USB 3.0 adapter, as seen in our testing that does and excellent job to show the capability of the memory card. Again that’s being picky o have an SD and USB 3.0 adapter simultaneously
– The Lexar USB 3.0 adapter gets quite hot during heavy and long file transfers

Glob3trotters “Top Product” Award – 4.5 out 5



A lot of thanks to LEXAR for supplying us with this test sample !


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