
SanDisk Ultra 256GB microSD
Score: 90/100
Silicon Power 512GB
Score: 100/100Rankings

A 512 GB microSDXC U3/V30/A2 card delivering up to 170 MB/s read and 150 MB/s write, rugged durability and high-endurance options, suited for 4K video, Android apps and demanding outdoor use.

The SanDisk 256GB Ultra microSDXC offers high capacity, fast read performance and rugged durability, but its write speed is limited and it lacks 4K video certification.
| Attribute | ![]() | ![]() |
|---|---|---|
256 GB | 512 GBbest | |
150 MB/s | 170 MB/sbest | |
30 MB/s | 150 MB/sbest | |
10 yearsbest | 5 years | |
| ↓ lower better | 4.5 g | 0.3 gbest |
Click an attribute name to sort · Green = best, red = worst (relative to this comparison)
| Attribute | ![]() | ![]() |
|---|---|---|
Storage & Capacity(1) | ||
Capacity (GB) | 256 GB | 512 GB |
Performance(4) | ||
UHS Speed Class | U1 | U3 |
Maximum Read Speed (MB/s) | 150 MB/s | 170 MB/s |
Maximum Write Speed (MB/s) | 30 MB/s | 150 MB/s |
Application Performance Class | A1 | A2 |
Warranty(1) | ||
Warranty Period (years) | 10 years | 5 years |
Physical(1) | ||
Weight (g) | 4.5 g | 0.3 g |

Products in the top-left offer the best value (high score, low price).

Professional reviewers highlight the Ultra 256GB as a solid, value-driven choice for Full HD video and Android app storage, praising its fast read speeds and rugged build while noting its limited write performance and lack of 4K support.
Everyday users appreciate the card's reliability, capacity, and durability, often noting it works straight out of the box and improves app responsiveness, but many complain about slower write speeds and the inability to handle 4K video.

“Works perfectly”

“Writes are slow on large transfers.”

“Fast read speeds make file transfers quick”




Professional reviewers consider Silicon Power's 512 GB U3 cards reliable mid-tier options that deliver solid 4K video performance and useful A2 app acceleration, highlighting durability, endurance features and a long warranty as key strengths, while noting they don't match the top speeds of SanDisk or Samsung.
Everyday users praise the cards for consistent 4K recording, good durability and the long warranty, especially noting the High Endurance model's reliability in dashcams, but also mention occasional speed variability, confusing model labels and incompatibility with the upcoming Switch 2.