I purchased this
Sandisk 32GB MicroSDHC Class 4 Memory Card over one month ago, for use in my
VIZIO 8-Inch Tablet VTAB1008. At the same time, I also purchased a higher-priced
PNY 32 GB microSDHC Card (P-SDU32G10-EFS2) which is supposed to be a 'class-10'. My benchmark results, however, show that the Sandisk class-4 card is actually faster - most of the time.
I used two sets of benchmark programs. One is called 'Flash Memory Toolkit v2.0', which measures the random read/write speed of files between 1MB and 15MB. The other one is called 'H2testw v1.4', which measures the sequential read/write speed using 1GB files. Here are my results: (see my uploaded charts in 'Customer Images' section for details)
- For smaller files (1-5MB), the Sandisk class-4 card gives an amazing write speed of 15-17MB/s, while the PNY 'class-10' card can only get 1-6MB/s
- For larger files (10-15MB), the Sandisk and PNY cards are about equal at around 8MB/s for write
- For huge files (1GB), the PNY did better at 9.5MB/S, while the Sandisk dropped to 5.5MB/s
- The read speeds of both cards are equally high at around 18MB/S (this number may be limited by the maximum speed of my card reader used)
What the above shows is that: When used in a typical digital camera (with file size 3-5MB), this Sandisk 'class-4' card is at least twice as fast as the PNY so-called 'class-10' card. But when used in a HD video camera (sequential writing of huge file), then the PNY card should perform better.
For a card to be marketed as a 'class-10', it must maintain a MINIMUM write speed of 10MB/s. So by this definition, the PNY card does not qualify since it cannot even achieve a MAXIMUM write speed of 10MB/s. This Sandisk card, on the other hand, exceeds the requirement of 'class-4' by a huge margin.
Sandisk seems to be the only flash memeory manufacturer that still gives honest, conservative speed class ratings. Any other manufacturers would have labeled this card a 'class-6' or even higher. As a matter of principle, I rather give my money to a company that promises less but delivers more, instead of to others that do the opposite.
The only problem with this package is that: the included
Sandisk MicroMate USB Card Reader (SDDR-121-GREY) does not work at all. I tested it with differet micro-SD/SDHC cards on three different computers. They all can recognize the drive, but not the memory card inside. Minus one star for that.