Review on 💾 Enhanced Search-Optimized SanDisk 16 GB Class 4 microSDHC Flash Memory Card by Raymond Simmons

I bought 2 of these cards from eTECH but received class 4 cards instead of class 2. I can't fault the seller for thinking it was just an upgrade, since the class rating doesn't account for random small block writes (which was relatively good for both cards), but this spec might be important if you're upgrading your OS from a real card run (Nook Color CM7 with SD etc.). The tests are listed below for each card and were run using an internal card reader connected to my mobile device via USB before data was written to the card. Neither card fully lives up to the Class 4 promise of 4MB/s sequential write speed - luckily for my use it doesn't matter, aside from the article listing it as Class 2 and the cards the Class 2 specs surpass ------------------------------------------------ -- ------------------CrystalDiskMark 3.0.1 (C) 2007-2010 hiyohiyo Crystal Dew World: [.]------------ -- ------------------------------------------------ -- -------* MB/s = 1,000,000 bytes/s [SATA/300 = 300,000,000 bytes/s] Sequential Read: 4.183 MB/s Sequential Write: 3.407 MB/512 KB Random Read: 4.126 MB /s 512 KB Random Write: 3.291 MB/s 4 KB Random Read (QD=1): 0.958 MB/s [233.9 IOPS] 4 KB Random Write (QD=1): 0.639 MB/s [155.9 IOPS ] 4 KB Random Read (QD= 32) : 1,191 MB/s [290.8 IOPS] 4 KB Random Write (QD=32) : 1,660 MB/s [405.2 IOPS] Test: 50 MB [J: 0, 0% (0.0/14.8 GB)] (x5) Date: 2011-05-06 00:35:15 OS: Windows XP Professional l SP3 [5.1 Build 2600] (x86)--------- ----------------------------------------- -- ------- ---------------------------------------- ------- ---- CrystalDiskMark 3.0.1 (C) 2007-2010 hiyohiyo Crystal Dew World : [.]--------------------- ------- ---- ---- --- -------------------------------* MB/s = 1,000,000 bytes/s [SATA /300 = 300,000,000 bytes/s] Sequential Read: 4.176 MB/s Sequential Write: 3.360 MB/s 512 KB Random Read: 4.113 MB/s 512 KB Random Write: 3.221 MB/s 4 KB Random Read (QD=1): 1.014 MB/s [247.6 IOPS] 4KB Random Write (QD=1): 1.646MB/s [401.9 IOPS] 4KB Random Read (QD=32): 0.927MB/s [226.3 IOPS] Random Write 4KB (QD=32) : 1,500 MB/s [366.2 IOPS] Benchmark: 50 MB [J: 0.0% (0.0/14.8 GB)] (x5) Date: 06/05/2011 00:44: 50 Operating System: Windows XP Professional SP3 [5.1 Build 2600] (x86)