I have tested the 16GB version of PNY microSDHC Class 4 Flash Memory Card, using three different benchmark programs. Here are my findings:
- According to CrystalDiskMark v3.01, this PNY card delivers Sequential Read speed of 21.8MB/s, and Sequential Write speed of 5.35MB/s when accessing 500MB files. But it has very poor Random Write speed for tiny (4KB) files, compared to other class-4 microSDHC cards by Sandisk or Kingston.
- According to H2testw v1.4 (which measures Sequential Red/Write speed of 1GB files), this PNY card achieves 4.97MB/s in Write, and 19.5MB/s in Read. This is consistent with the Sequential Read/Write speed reported by CrystalDiskMark.
- According to Flash Memory Toolkit 2.00, the Read speed of this PNY card is consistently high at 19-20MB/s, regardless of file size. Its Write speed, however, varies greatly with file size. For small files (1-2MB) its write speed is just around 2MB/s. For larger files (4-10MB) it improves to around 4MB/s. See the screenshot I uploaded to 'Customer Images' section for details.
My benchmark results confirmed that this PNY card qualifies as a 'class-4' (which only requires a minimum Sequential Write speed of 4MB/s). However, its Random Write speed for small files is painfully slow. When used in a tablet or smart phone, the random write speed of the memory card is more critical. Therefore this PNY card will perform a lot slower than other class-4 cards by Sandisk or Kingston. But as of this writing the PNY card is priced higher, so it is just not a good value for your money.