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Old Jul 16, 2004, 2:36 PM   #11
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Belz wrote:
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Next is for Jim C

You say that "There are two main parts to flash memory cards, the controller and the memory cells. Memory cells go bad over time. So, flash memory cards aredesigned to automatically and transparently map out memory cells that go bad (or when they reach a predefined limit of erase/write cycles"

does this mean that after time like a lith-ion battery it just goes dead and you need to replace it?
Memory Cells do have a finite lifespan. However, they are designed for hundreds of thousands of erase/write cycles (at least in CompactFlash media). So, chances are, they'll last for many years of service.

I think part of the problem ismemory density (especially with Secure Digital Media, because of it's tiny form factor). Also, you see a far greater number problems in larger media sizes.
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Old Jul 16, 2004, 2:39 PM   #12
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FrankO wrote:
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I wonder what kind of data loss I would experience if I were shooting at 2592*1944 megapixels at the highest quality jpeg setting. One photo in TIF is about 14.5 MB as compared to 1.5 MB in jpeg. That indicates to me that there is a tremendous difference in data stored, although to the naked eye it may be totally nondetectable.... 5 years it won't even matter, it'll all be faster and better.
Because JPEG is a compressed format, theuncompressed size is much larger. It's simply decompressed as it's viewed. If you take a JPEG file, then resave it as TIFF (uncompressed), you'll see it's file size grow to near what a TIFF from the same camera model would be.
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Old Aug 3, 2004, 1:38 AM   #13
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great info jim!!!!

Has anyone tried using cards made by ATP Electronics? I'm a rep from the company and I've been sent out to "interface" w/ people that have questions.

Yeah, SD cards are faster due to the fact that MMC cardsare restricted by a smaller number of data transfer pins compared to the SD cards. This will change w/ the next generation MMC cards dubbed the "MMC Power" for the full size MMC cards and the "MMC-Mobile" for the RS-MMC cards. Note that this next generation will of course be backwards compatible.

In terms of the lifetime of the flash ICs, the "stated" lifetimeis >100,000 read/writes for cards using Samsung NAND ICs (largest flash IC producer). For Toshiba/Sandisk NAND ICs, the lifetime is >10,000 read/writes. If these numbers don't seem high to you, then just keep in mind that most flash card manufacturers (including ATP) have warranties on these cards.

JimC is certainly correct about the controller being a vital part of these cards, as they pretty much determine the compatibility potential and transfer speeds.... Because different cards use different controllers, therevariation in transfer speeds between cards.

-Jeff

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Old Aug 3, 2004, 1:39 AM   #14
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oh yeah forgot to mention..... :lol:

If youare interested in ATP cards, here's a review done by howard chui of howardforums.com of our 512MB MMC cards. Included are benchmark comparison tests!

http://www.howardchui.com/modules.ph...&artid=166


-Jeff

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Old Aug 4, 2004, 12:00 AM   #15
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SD Card are easily available and cheaper but MMC are hard to find and expensive. Just my experience
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