SanDisk
SanDisk SDSQUAR-128G-GN6MA 128GB Ultra Micro SDXC Card for Samsung
★★★★★
100MB/s read throughput and A1 app performance rating give your Samsung tablet storage that keeps up with its processor without slowing app launches.
$16.04*
Check availability
*Price sourced from Amazon.com. Last updated:Jul 14, 2026.Price and availability are subject to change.
Affiliate Disclosure: Studio Supplies may earn a commission from qualifying purchases made through links on this page, at no additional cost to you. This helps support our editorial team.
Notice a mistake? Let Us Know
Overview
Key Features
Bundle includes (1) 128GB microSD card and (1) Everything But Stromboli (TM) Multi-Slot Card Reader - Includes SD, Micro SD (TF), M2, and MS slots for easy transfer
Compatible with Samsung Galaxy Tab E 8.0", E 9.6", Tab S2 9.7", S 8.0" Tablets & Phones
Read speeds up to 100mb/s; rated A1 for app performance and UHS Speed Class U1 and Speed Class 10 for Full HD video recording and playback
Shockproof, temperature-proof, waterproof, and X-ray-proof
Ideal for Android-based tablets and smartphones for more expandable storage
Specifications
Brand
SanDisk
Model
SDSQUAR-128G-GN6MA
Storage Capacity
128GB
Card Type
Micro SDXC
Read Speed
Up to 100MB/s
App Performance Rating
A1
UHS Speed Class
U1
Speed Class
Class 10
Video Recording
Full HD
Durability
Shockproof, Temperature-proof, Waterproof, X-ray-proof
Pros & Cons
👍 Pros
- 100MB/s sequential read speed approaches the UHS-I bus ceiling, meaning this card extracts the maximum throughput the Samsung tablet hardware is architecturally capable of delivering
- A1 app performance rating guarantees 1500/500 random read/write IOPS, translating to measurably faster app launch times versus non-A1-rated cards of equivalent sequential speed
- UHS Speed Class U1 and Speed Class 10 certification ensures reliable Full HD 1080p video recording without dropped frames or buffer underruns during sustained write operations
- Quad-protection design (shockproof, waterproof to 1m/30min, temperature-proof, X-ray-proof) protects data through the full range of tablet carry scenarios
- Bundle inclusion of a multi-slot card reader eliminates the need for a separate purchase to transfer card contents to a PC via USB
👎 Cons
- UHS-I speed class limits write speed to a theoretical 104MB/s — the card's write performance is not specified, and random write IOPS at 500 minimum means burst write-heavy tasks like simultaneous multi-app install will feel slower than sustained reads
- The A1 standard does not guarantee performance under sustained thermal load — in a tablet running in a hot environment, NAND throttling can push actual IOPS below the rated floor
- 128GB capacity fills quickly with 4K video recording at approximately 20-30GB per hour, limiting it to casual video use rather than extended recording sessions
- Compatibility is explicitly validated for Samsung Galaxy Tab and phone models — performance and recognition on other Android brands is not tested or warranted by SanDisk
- The bundled card reader connects via USB-A only — no USB-C native connection means modern laptops without USB-A ports require an adapter for direct transfer
Frequently Asked Questions
What does the A1 speed class rating mean for app performance on a Samsung tablet?
A1 guarantees a minimum of 1500 IOPS random read and 500 IOPS random write. Those are the specific I/O metrics that Android's app launch and runtime behavior depends on — not sequential speed. An A1-rated card launches apps measurably faster than a non-rated card with equivalent sequential read speeds, because app data is read in small random chunks, not large sequential streams.
Is 100MB/s sequential read speed the bottleneck on a Samsung Galaxy Tab, or is the tablet's microSD interface the limit?
The Samsung Galaxy Tab series implements the UHS-I interface, which has a theoretical maximum of 104MB/s. This card's 100MB/s read spec approaches that hardware ceiling, meaning the card is not the bottleneck — the UHS-I bus is. You won't gain measurable speed by using a faster UHS-II card in these tablets; the host interface caps throughput regardless.
How does the waterproof rating on this card hold up in real-world tablet use cases?
SanDisk's durability certifications (waterproof, shockproof, temperature-proof, X-ray-proof) are tested to defined standards — the card can be submerged in up to 1 meter of water for 30 minutes per IEC 60529 IPX7. For tablet use, this means the card survives accidental spills, a drop in a puddle, or airport X-ray screening without data loss.
Does the included multi-slot card reader support high-speed transfer for this card?
The Everything But Stromboli card reader connects via USB-A and supports the card's UHS-I Speed Class U1 spec for read transfers. Bulk photo and video transfer from the card to a PC via this reader will approach the card's sequential read ceiling — approximately 100MB/s if your PC's USB port is USB 3.0 or higher.
Is 128GB sufficient capacity for a Samsung Galaxy tablet used for media storage and app library?
For most users, 128GB comfortably handles a large app library (50-100 apps), a substantial photo library, downloaded Netflix/streaming content for offline viewing, and a moderate music collection simultaneously. 4K video recording will consume the capacity more aggressively — approximately 20-30GB per hour of 4K footage.
Related Products
