Originally Posted by nht
Not this again. There are two general types of Flash: SLC and MLC...with SLC being more reliable and MLC less (ignoring NOR and NAND for the moment). The difference between the two is far less today than before...or perhaps more accurately MLC has become good enough using a host of fancy tricks.
Apple uses MLC flash in the iOS devices. For example the iPhone 4S and the new iPad are sporting 24nm Toshiba THGVX1G7D2GLA08 16 GB MLC NAND Flash. iSuppli thinks it costs $19.20 while the 32GB around $38.40 and the 64GB $76.80.
Some USB sticks actually used SLC flash for performance. The older Corsair GTs had SLC but MLC is fast enough and reliable enough for new GTs to have MLC NAND flash to some grousing among those that still expect the more expensive SLC NAND in the GTs.
So the Flash type doesn't tell you that much about the grade of the flash these days...its pretty much all MLC except for a few enterprise drives. High end MLC flash is pretty good. Or more accurately the high end MLC flash controllers are very good, increasing the raw 3-5K P/E (write) cycles to an effective 30-50K P/E cycle. One reason that Apple bought Anobit was to keep this bit of technology to itself. There's probably some Anobit magic on the A5 SOC. Apple can afford to use "value" flash (24nm high density, high speed, low reliability flash) and end up with moderately high reliability as well.
SO the most important difference between "high end" flash seen in the iPhone and "low end" flash seen in low grade USB sticks is the iPhone has a high end controller and the USB stick has some craptastic eMMC controller. High end USB sticks are often pretty good. Certainly high end SDHC cards are just as good or better. For example the Transcend 32GB Class 10 SDHC is using SLC Flash and costs all of $32 retail on Newegg.
So there's no misunderstanding. Apple CAN afford to offer more flash storage but that's probably a good chunk of the margin right there. That's not likely to change but has little to do with what flash is costing Apple. That's also why we're very unlikely to ever see a SD card slot on the iPad.
Nope! There are three basic types of flash NAND. SLC, MLC and TLC. SLC is the most reliable. MLC is next. TLC is the least reliable. TLC is also the cheapest, and is often used in the cheapest sticks, and sometimes in the cheapest SD and Compact Flash cards.
It's true that TLC is a relation to MLC, which is just two bits, whereas TLC is three, but is also moving to four at some point. But they have to be made differently enough that they can be considered a different type, as SLC and MLC are. It's the newest type as well.
If what you said about the difference between SLC and MLC drives being different mainly because of the controllers were true (it isn't) then I wouldn't have posted what I did. But enterprise quality drives use SLc almost exclusively, which is why they cost so darned much. Even then, they have a greater percentage of overage in the amount of flash they use for greater reliability over time as the flash begins to fail. There are also semi-enterprise level drives that cost more than consumer models, but less than the real enterprise models that do use a higher rated MLC. But they can have as much as 28% overage in flash to make up for the lower reliability, despite the sophisticated controllers used today.
None of this is relevant to Apple's iOS devices, as they all use MLC. But a normal markup on part prices for manufacturers is between 100 and 300%. Apple isn't asking too much for it.
You should go to Newegg and look at prices for HDD's. You'll find that those branded with HP, IBM, Lenovo, etc, cost several times as much as those from Seagate, WB, etc. this is normal.
If Apple pays $50 for flash, I would expect them to charge between $100-150 for it in the device pricing. The Motorola tablet cost $200 more for an extra 32 GB when it first came out, as did the 3G/GPS add-on. And the basic tablet itself cost $599.