Hi John ... Thanks for posting this info.
Shel > [Original Message] > From: John Celio > > Are all SD cards more or less equal, given storage volume? > > Oh god no! Not even close. > There are some very important things to know about memory cards before you > go and buy one, but unfortunately these things can be hard to find out from > the memory manufacturers. > > One of the things I do at my job is image recovery for customers whose > memory cards have become unreadable for whatever reason. I get about six or > seven image recovery requests per week, and I've noticed some trends: > > -- The majority of memory cards that come to me with problems are those > cheapass SanDisk cards that are sold just about everywhere (especially at > places like Costco and Wal*Mart). Note: this group does not include Ultra > or Extreme cards. > -- The next largest group of cards to come to me are "no name" memory > cards. "No name" refers to cards from a brand no one (in my lab, anyway) > has heard of or cards with no brand at all. Many of these cards come from > online retailers who package them with a camera to sweeten the deal, or from > the customer having to purchase more memory from a tourist trap while > travelling. > -- The smallest group consists of "professional" cards. In the last couple > weeks, I've seen two SanDisk Ultra IIs, one SanDisk Extreme, and one Lexar > Professional (which is the brand I use, and which I actually rarely see come > to me with problems). > > What separates these groups? > > Memory manufacturers generally have three tiers of quality, and they affect > the speed and reliability of the memory in each tier. > > Tier 3: This is the cheap stuff. Cheapass SanDisk cards fall in this > category, as well as most other cheapass memory you find (this includes > cheapass memory you can buy for your computer and whatnot). If you were to > open a tier 3 memory card, you would see more than one piece of flash > memory. If, for example, you bought a 512mb card and opened it up, you > would most likely see four pieces of 128mb flash memory inside. These > modules are cheaper to produce, and so the manufacturers produce them en > masse and combine them into larger capacity cards. More memory modules > means higher chances of getting defective memory, as well as slower transfer > rates, but lower prices. Consumers buy this stuff because they think > they're getting a good deal, but in fact they're playing roulette with their > data. > > Tier 2: This stuff is usually produced from a couple memory modules, but not > as many as Tier 3 cards. The modules have higher capacities (in some cases > there is only one piece of memory in tier 2 cards) and are usually produced > under tighter quality controls. These cards are faster than tier 3 cards, > but not always as fast as Tier 1 (though they can be very fast). > > Tier 1: This is the high-end stuff. You generally get what you pay for with > tier 1 cards. They are made from a single memory module, and are generally > very fast (depending on the technology available at the time they were > designed, of course). They are produced under the tightest quality > controls, and are often tested at the factory before being shipped. Lexar > Professional, SanDisk Extreme, and SanDisk Ultra cards fall under this > category, but in my experience with so many bad cards, the Lexar > Professional cards seem to be the most reliable (though admittedly not > always as fast as the SanDisk cards) > > > So, after learning all this, it has become my opinion that, when buying > memory, one should spend the extra money and get professional-quality stuff. > You really do get what you pay for. > > John Celio
