1 Star topics are like watching a group of blind people describe an elephant. No wonder no one has the full picture, but many Canon owners believe these cards are fake. SD card technology is very complex, the class system is often misunderstood and there is a long history of compromised cards showing up on eBay or even from reputable retailers who have been scammed. Kingston cards are the most commonly counterfeited (or taken from the midnight production cycle); This is because Kingston has about a third of the flash card market and they don't counterfeit their own chips, but any manufacturer can be counterfeited. It's not profitable to buy cheap cards from eBay or less reputable sources. An SD card contains a controller chip and flash memory chips, even microSD versions. Understand that SD stands for Secure Digital and that security is provided by controller-driven cryptography (MMC cards didn't have such bloat, but Hollywood's DRM requirements ensured they would go away). The controller can be quite powerful: the Samsung SD controller is a 32-bit ARM TDMI chip with 128KB of codespace - that's the power of a cell phone. It handles I/O and fading (when the card slowly wears out its NAND nodes after about 100,000 accesses, so writes are randomized and monitored), factory self-tests, and a variety of other functions, but can also be programmed to report incorrect memory capacity. Sometimes the firmware of the controller or its crypt or something else on certain cards causes problems with certain hardware, such as was the case with the Samsung Galaxy III and possibly Canon cameras. It's usually determined that the card meets dot Org's SD card specs and the hardware is to blame, but you never know for sure. To check the actual capacity of your card, use the free H2testw. It writes the full amount of data to the card and then reads it back (this destroys everything that was on the card). It can take over an hour with a 32GB card, but it will tell you if the card is actually 32GB or has problems. It also gives you read and write speed numbers, but it's not clear if the numbers are for random read/write or sequential read/write. Sequential recording is what photographers and videographers are most excited about. Sometimes a Class 6 card can be tested faster than a Class 10 card when using computer read/write tests, or even in a camera not designed for higher capacity cards. This is because they use smaller blocks (there is no cache on the SD card). Explaining the meaning of this goes too far for a Revain review, and modern devices and their firmware shouldn't have that limitation. To test random and sequential read/write speeds, use CrystalDiskMark, also free. Do the complete sentence; it doesn't take much time. CrystalDiskMark requires the card to be formatted and the most reliable way to do this is to use the free tool from sdcard dot org. A 32GB card may report 39.9GB before formatting and 29.8GB after; Don't worry, you weren't robbed. Unfortunately, even on Linux, there is no easy way to read the Vendor ID from an SD card to determine who actually made the card, as you need to connect it directly to the motherboard. An SD to USB adapter won't work because it doesn't leak data from the drive, which almost all computers have. But what does it matter to you if the map is as big and fast as advertised? What about the 32GB Transcend SDHC C10 card? Here are the full CrystalDiskMark test results: Transcend 32GB SDHC C10 ------------------------------------------------ --- - --------------CrystalDiskMark 3.0.2 (C) 2007-2013 hiyohiyo Crystal Dew World : [ .]----------------- ----- ---- ----------------------------------------- ----- ---- ---* MB/s = 1,000,000 bytes/s [SATA/300 = 300,000,000 bytes/s] Sequential Read: 19.953 MB/s Sequential Write: 13.786 MB/s 512 KB Random Read: 19.618 MB/s 512 KB Random Write: 13.827 MB/s 4 KB Random Read (QD=1) : 3.003 MB/s [733.2 IOPS] 4 KB Random Write (QD=1) : 1.414 MB/ s [345.1 IOPS] 4 KB Random Read (QD=32): 3.491 MB/s [852.3 IOPS] 4 KB Random Write (QD=32): 1.842 MB/s [449.8 IOPS] Test: 50 MB [F: 0.0% (0.0/29.3GB)] (x5) Date: 05 /12/2013 06:19:47 PM So you can see that the sequential write speed, which is important for a photographer or videographer, is over 13 MB/c, more than 30% higher than the C10 specification. The other speeds aren't bad either. It can't be that this card is too slow for a modern photo or video camera that works perfectly. Revain also has a 32MB Sony SD card at a very attractive price. Here are the full CrystalDiskMark results for it: Sony 32GB SDHS USH-I Sequential Read: 19.998MB/s Sequential Write: 14.115MB/s 512KB Random Read: 19.772MB/s 512KB Random Write: 13.173MB/s Random Read 4KB (QD=1) : 3,682 MB/s [899.0 IOPS] 4KB Random Write (QD=1) : 2,302 MB/s [561.9 IOPS] 4KB Random Read (QD=32) : 4,517 MB /s [1102.8 IOPS] 4KB Random Write (QD=32): 2.323 MB/s [567.0 IOPS] So Sony is slightly faster, 40% over spec. H2testw also reported full capacity and no errors for this card, so they're both top notch (Sony doesn't ship in a small case, and Transcend's case is and will be about twice the size it should be). do not fit in the small pockets of a modern camera bag. Great deals.) For reference only, here are the results for a modern USB stick: SanDisk Ultra 32GB USB Stick Sequential Read: 22.508MB/s Sequential Write: 7.985MB/s 512KB Random Read: 22.365MB/s Random Write 512 KB : 1.767 MB/s 4 KB Random Read (QD=1) : 3.719 MB/s [ 908.1 IOPS] 4 KB Random Write (QD=1) : 0.520 MB/s [ 126.9 IOPS] 4 KB Random Read (QD=32): 3.871 MB/s [945.0 IOPS] 4 KB Random Write (QD=32): 0.482 MB/s [117.7 IOPS] As you can see, this USB drive is reading , e.g. faster than SD cards when playing music, running software or searching for data, showing that it's well-optimized for its intended functions. Also, anyone who thinks they lost their SD card data can use the free tool za-recovery to recover pictures or recover everything (!) using the free PhotoRec tools. So, if people want to whine about those SD cards in their particular cameras, they should do these simple free tests and draw their own conclusions. about whether the cards are "too slow". Cards are objectively tested above specification. And both work fine on my non-Canon cameras and camcorders. I think they got a bad rap here from people who don't have the full picture, so to speak. I will also post this as a review and also on the Sony 32GB page. I hope you found it informative.
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