The SanDisk Ultra microSDXC 128GB memory card is optimized for smartphone, tablet, or camera users looking to maximize their storage space. It is compatible with Android and Windows phones and can be used with any SD card accepting camera (it comes with an SD card adaptor). While it does offer the most storage available in any microSD card on the market today, the user does sacrifice some performance; at a reported read speed of 30MB/s, it is one of the slowest microSD cards that SanDisk makes. However, for many users this trade-off would be an easy one to justify; this card could be fully appreciated by anyone that uses their phone or camera to capture lots of HD video or images without wanting to clear the card as frequently.
Using our , we measured transfer speeds from the SanDisk Ultra microSDXC 128GB with IOMeter. Its sequential activity was measured at 44.66MB/s and 14.29MB/s for read and write, respectively, and random large-block performance was found to be 43.98MB/s and 2.45MB/s for read and write, respectively. Both read values were higher than those reported by SanDisk; the company doesn't disclose expected write speeds other than to say they'll be slower than the read performance.