by Josh Shaman

Samsung microSDXC Pro Series Review (MB-MGCGB)

The Samsung microSDXC Pro Series is a memory card engineered primarily with high-end smartphones and tablets in mind, and Samsung offers the microSD in capacities of 8GB, 16GB, 32GB or 64GB. As a member of the Samsung Pro Series (which also features a standard SD card), this flash card carries a more robust performance spec than typical flash cards - it comes rated at 70MB/s for read activity and 20MB/s for write activity. That read transfer rate means that users browsing media files on their tablets and smartphones won't be waiting for long load times, and when they write data over, that process will also have a boost over standard cards. The Pro Series is also rated with the UHS Speed Class 1 (U1) and Class 10 video recording ratings that signify high speed data transfers capable of handling HD content including Full HD video at 1080p.

Onto format differentiation, for those unfamiliar, the SDHC (high capacity) format supports a capacity up to 32GB, while SDXC (extended capacity) supports a theoretical 2TB maximum. Thus the 8GB, 16GB and 32GB are SDHC while the 64GB is SDXC. For the intended applications, that amount of storage should be more than enough for most users, doubling, tripling, or even quadrupling the native capacity of their mobile device.

The Samsung microSDXC Pro Series also delivers an elevated level of durability. To start, the flash cards are water-proof and have proven to maintain operational functionality even after submersion in seawater for 24 hours. Amongst other hazards, Samsung says that their Pro Series cards can stand up to shock caused by dropping the cards inadvertently, temperature (with an operational rating of -13ºF to 185ºF), and even X-rays.

The Samsung microSD Pro Series is available now at a street price of $14 for the 8GB, $25 for the 16GB, $33 for the 32GB and $57 for the 64GB. The cards also feature a 10 year warranty. Our tester cards are the 32GB microSDHC and the 64GB microSDXC.

Samsung microSD Pro Series Specifications

  • Capacities
    • SDHC: 8GB, 16GB, 32GB
    • SDXC: 64GB
  • Data Transfer Speed Up to 70MB/s Read, Up to 20MB/s Write (UHS-I Interface)
  • Voltage: 2.7~3.6V
  • Operating Temperature: -25ºC to 85ºC
  • Non-operating Temperature: -40ºC to 85ºC
  • Dimensions (WxHxD): 0.59" x 0.43" x 0.04"
  • Weight: .017 oz
  • Warranty: 10 Years Limited

Design and Build

The Samsung microSDXC Pro Series has the same design that those familiar with Samsung products will recognize. The card is all black with product information on the front including the capacity. 

SDXC host devices accept any prior-gen SD cards, and SDHC host devices accept SDXC as well as they feature the same interface. 

The rear of the card features some model information and the 8 gold connector pins.


Using our Consumer Testing Platform, we measured transfer speeds from the Samsung microSDXC Pro Series 64GB with IOMeter. Sequential read speeds measured 66.26MB/s, while write activity hit 19.63MB/s. Random large-block transfers measured 62.24MB/s read and 19.29MB/s write.  We also tested the Pro Series 32GB microSDHC with IOMeter, and sequential speeds hit 67.94MB/s for read activity and 22.78MB/s for write activity. Random large-block transfers measured 63.24MB/s read and 5.25MB/s write. 

It was impressive to see very little degradation as we transitioned from the sequential workload test to the large-block scenario with the 64GB card, and the same applied with read activity on the 32GB card. However, there was a delta in random large block write activity with the 32GB card. All data considered, the microSD Pro Series cards performed relatively close to Samsung's quoted marks of 70MB/s and 20MB/s.

For a comparable, we tested the SanDisk Extreme microSDXC UHS-I 64GB. Sequential read and write speeds measured 89.41MB/s and 58.51MB/s respectively, while random large-block transfers measured 82.10MB/s read and 41.54MB/s write.


The Samsung microSD Pro Series line is comprised of memory cards that range from 8GB to 64GB in raw capacity and are designed to expand the native capacity of mobile devices such as tablets and smartphones. However, unlike standard memory cards that features transfer rates at 10-25MB/s, the Samsung microSD Pro Series cards are rated at 70MB/s for read activity and 20MB/s for write activity, and they also feature the UHS Speed Class 1 and Class 10 video recording ratings. That means that users accessing media from their cards won't experience long loads, and the cards even support Full 1080p HD video. Three capacities (the 8GB, 16GB and 32GB) are SDHC cards, as that format maxes out at 32GB, and the 64GB is a SDXC card. Samsung also rates these cards to handle extreme conditions. They are water-proof and can withstand submersion in seawater for up to 24 hours. Additionally, the drives can operate under temperatures from -13ºF to 185ºF.

In testing, the Samsung microSDXC Pro Series came very close to delivering the 70MB/s read and 20MB/s write performance that Samsung quoted. Also, in our random large-block workload, the Pro Series 64GB provided near-identical figures. However, the Pro Series 32GB saw a drop-off to 5.25MB/s for random writes. We compared these figures to the performance of the SanDisk Extreme microSDXC, which is SanDisk's top of the line microSDXC format card. In comparison, the Samsung microSD Pro Series lagged behind a bit. Yet, the Samsung flash card is nearly $40 cheaper (approximately $62 versus $100 at 64GB). That said, at the price-point, the Samsung microSDXC Pro Series provides considerable performance, especially for its intended applications in high-end smartphones and tablets. 


  • Relatively low cost at roughly $1/GB on the higher capacities
  • Performance similar to quoted rates


  • Pro Series is tops - no higher performance in the microSDXC line
  • microSDHC 32GB random writes took a hit

Bottom Line

The Samsung microSDXC Pro Series provides plenty of transfer speed to meet the demands of users with mobile devices looking for more performance than a typical flash card at a price that's quite reasonable. 

Samsung microSDXC Pro at

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