The latest flash-based SD memory cards with UHS-I deliver up to 63 MB/s throughput. Users who want to exploit that performance need to pay attention to a few details, like making sure they upgrade to a USB 3.0 card reader. Which card is the fastest?
512 KB Random Read/Write
Random read operations using a 512 KB block size work rather well on all the cards, as 16.7 MB/s is the minimum performance we see. Kingston and SanDisk are the only two vendors that provided UHS-I cards. This becomes very obvious when looking at the results.
Random writes using the same 512 KB blocks requires way more time for these cards to organize and store data (read-modify-erase-write). This is not a typical application scenario, but it brings a few cards down and shows some others ahead.
4 KB Random Read/Write
Random read and write operations using 4 KB blocks result in more severe performance drops. You see 2.3-3.7 MB/s total bandwidth in random reads and only a few kilobytes per second in random writes.
- High-Speed And High-Capacity SD Memory Cards Tested
- SD Memory Card Performance And Standards
- USB 3.0 Card Reader: Pretec P240
- Kingston Ultimate XX (8, 16, 32 GB)
- Lexar Professional 133x (16, 32 GB)
- PQI SDXC C10 (64 GB)
- SanDisk Extreme Pro (16 GB)
- Comparison Table And Test Setup
- Benchmark Results: Access Time And I/O Performance
- Benchmark Results: Random Read/Write
- Benchmark Results: Sequential Reads/Writes
- Benchmark Results: Read/Write Throughput
- Benchmark Results: Combined Read/Write Throughput