Devices SD

Pretec MicroSDHC 32 GB Class10 UHS-1

Yet another MicroSDHC card
Pretec MicroSDHC 32 GB

CrystaDiskMark 5 results
CrystalDiskMark 5 Pretec MicroSDHC 32GB

Flash SD

Modern 32 GB SDHC UHS-1 cards I/O speed test

Some new SD cards speed test

TDK 32 GB SDHC UHS-I Class10 t78717
Transcend Premium 32 GB SDHC UHS-I Class10 TS32GSDU1
SanDisk Extreme SDHC UHS-I Class10 SDSDX-032G-X46

Sequential Read (MB/s) 52.090 88.012 46.786
Sequential Write (MB/s) 14.136 38.338 42.927
Random Read 512KB (MB/s) 44.635 69.408 40.880
Random Write 512KB (MB/s) 0.659 13.426 29.822
Random Read 4KB (QD=1) (MB/s) 2.818 2.540 3.031
Random Write 4KB (QD=1) (MB/s) 1.077 0.509 1.600
Random Read 4KB (QD=32) (MB/s) 2.825 2.736 2.877
Random Write 4KB (QD=32) (MB/s) 0.852 0.423 1.529
Devices SD

SanDisk ImageMate SDDR-289 (UHS-1 USB 3.0)

Reading some old posts:

SanDisk Extreme 30 MB/s SD Card
SanDisk SDDR-199
SD Cards test with SDDR-1999

Now I know what was wrong with 30MB/s SanDisk Extreme SD cards. 30 MB/s was not standard bus speed for SD. So it is seems like only (one?) card reader from SanDisk was supporting that speed. And it was not a good idea to buy 30MB/s cards. Actually theoretical maximum speed for normal and high speed SD cards was 12.5 MB/s and 25MB/s (read as 10MB/s and 20 MB/s in real life). And, by the way, USB 2.0 (480 Mbit/s) has reallife speed for cardreader/hdd/etc ~ 30 MB/s at maximum.

New SD card standards are UHS-1 with 50 MB/s and 100 MB/s (read as 45 MB/s and 90 MB/s) and UHS-II with 156 MB/s and 312 MB/s.

So now some examples of UHS-1 standard in use:

SanDisk ImageMate SDDR-289 (USB 3.0)

SanDisk 16 GB UHS-1 45MB/s

USB 2.0 is not enough to get 45+ MB/s that is why UHS-* cardreaders must be USB 3.0 or other modern high speed interface.

Card formated to exFAT. Cardreaders setting “optimized for performance” in Windows 7.

USB Reader Card Read MB/s Write MB/s
USB 3.0 UHS-1 UHS-1 45MB/s 39MB/s 24MB/s
USB 2.0 UHS-1 UHS-1 45MB/s 26MB/s 16MB/s
USB 2.0 non UHS-1 UHS-1 45MB/s 18MB/s 14MB/s

Card Formatted to FAT32 by SD Formatter 3.1

USB Reader Card Read MB/s Write MB/s
USB 3.0 UHS-1 UHS-1 45MB/s 36MB/s 32MB/s
USB 2.0 UHS-1 UHS-1 45MB/s 25MB/s 20MB/s
USB 2.0 non UHS-1 UHS-1 45MB/s 18MB/s 17MB/s

speed tested with Flash Memory Toolkit “File Transfer (5MB)”