Bad CF Card Doing This?? at DVinfo.net

Jonathan Warren · December 19th, 2010, 05:29 PM

I am using a Transcend 32 GB CF card. I have used this card for several months now without a problem, the most I would use of it would normally be less than 20 gigs at a time before I transfer and format. Yesterday I shot a lot of video and a few pics nearly filling the card up, and some of the last few pics had this problem, and a couple of the videos would not open. It wasn't all of the last few, just some here and there.

Daniel Epstein · December 23rd, 2010, 09:09 PM

Yes it could be the card. Try and test out other cards and see if the problem persists. If it doesn't persist try the card which had the problems again. You will probably find it is the card.

Bruce Foreman · December 23rd, 2010, 10:13 PM

Likely a combination of the card and almost filling it up. In the current Digital Photo issue, buyer's guide portion, the section on storage has a reminder pertaining to hard drives that it is in the last 10% of capacity that most "problems" occur.

I've encountered this in the days when a 30MB hard drive was "massive" storage. Twice I had "scrambled" files before I learned the file allocation table has a harder time keeping track of where portions of files are written as you get close to filling up the media.

Same principle applies when using flash media and I typically try to stop and change cards when I have 75% capacity used, so your habit of stopping at about 20GB on a 32GB card is not a bad idea.

The second part of the issue may be the Transcend card. While Transcends are quite a bit better on reliability than say, Patriot, A-Data, Dane-Elec and several other "bargain" brands around, they still experience more problems than Hoodman RAW or SanDisk media do. Transcend users are quick to challenge a statement like mine with "used Transcend for many months with no problems", or "never had a problem" but several have found out that buffering problems can occur if files are deleted from the card without formatting before using on the next project.

I recommend you use SanDisk or Hoodman RAW. If using SanDisk be sure it is one of the newer cards with UDMA.

Jonathan Warren · December 24th, 2010, 12:49 AM

I'll try to do some tests. I have 3 of the Transcend 32 GB cards and I'll fill each one up as much as possible to see if they have problems towards the end of free space. Or if it was just the one, or if it was just a fluke. I'll post my results in the next couple of days. Thanks for the info.

Bruce Foreman · December 25th, 2010, 01:26 AM

All those tests will tell you is that at that during the tests you found a problem or had no problem. They will tell you nothing about what lies in store later on. It's not an "absolute" sure thing that you will see problems as you fill the card up. It's simply that the "chances" of the file allocation table not keeping up with where "stuff" goes rise "astronomically" (term used in some articles I've read) the closer you get to filling the media up. It may or may not happen in your tests or it may not happen until the next time you use the card or the 13th time you use it (on a project, of course).

SanDisk is not "immune" from the file allocation table error thing, but it does seem to experience somewhat less in the way of problems with that. Nonetheless it is still a good idea to stop at about 75% to 80% card capacity and change to a fresh formatted card.

The accounts of Transcend failure I've seen were from people who felt they had no problems in any prior use, but suddenly on a critical project they "lost" data. That's a hard way to find out.

Question I asked myself was (even though I'm retired and don't "shoot for hire" anymore), how well could I "afford" failure through not using the best media I could? Most of my "projects" are on a personal level, not really for others and I don't care to take risks by using "bargain" media, and I place Transcend in that category.

So I pay the price for SanDisk, bang my head against the wall, and roll on. But I've had no data failures, not even when I got so engrossed I filled a few cards up.

Yes, there have been some who experienced problems with SanDisk media. But far fewer than with anything but Hoodman RAW. And I've seen several reports that people who sent a "bad" card back to SanDisk got as a reply, "Uh...Sorry, not one of ours".

SanDisk is probably the most counterfeited media out there. Counterfeit copies seem to abound on ebay.

Jon Braeley · December 25th, 2010, 08:05 AM

I no longer use 32Gb cards and stick with 16Gb and work within these limits.

Since doing this I have never had an error, so I think the 32Gb card size is the problem. I've seen many posts from 32Gb card users about errors and corrupted files but very little with 16Gb cards.

And most of my 16Gb cards are Transcend with a few SanDisk.

December 19th, 2010, 05:29 PM	#1
Jonathan Warren New Boot Join Date: Jul 2008 Location: Springfield, MO Posts: 6	Bad CF Card Doing This?? I am using a Transcend 32 GB CF card. I have used this card for several months now without a problem, the most I would use of it would normally be less than 20 gigs at a time before I transfer and format. Yesterday I shot a lot of video and a few pics nearly filling the card up, and some of the last few pics had this problem, and a couple of the videos would not open. It wasn't all of the last few, just some here and there. Attached Thumbnails

December 23rd, 2010, 09:09 PM	#2
Daniel Epstein Trustee Join Date: Jan 2006 Location: New York, NY Posts: 1,267	Yes it could be the card. Try and test out other cards and see if the problem persists. If it doesn't persist try the card which had the problems again. You will probably find it is the card.

December 23rd, 2010, 10:13 PM	#3
Bruce Foreman Trustee Join Date: Nov 2006 Location: San Angelo Texas Posts: 1,518	Likely a combination of the card and almost filling it up. In the current Digital Photo issue, buyer's guide portion, the section on storage has a reminder pertaining to hard drives that it is in the last 10% of capacity that most "problems" occur. I've encountered this in the days when a 30MB hard drive was "massive" storage. Twice I had "scrambled" files before I learned the file allocation table has a harder time keeping track of where portions of files are written as you get close to filling up the media. Same principle applies when using flash media and I typically try to stop and change cards when I have 75% capacity used, so your habit of stopping at about 20GB on a 32GB card is not a bad idea. The second part of the issue may be the Transcend card. While Transcends are quite a bit better on reliability than say, Patriot, A-Data, Dane-Elec and several other "bargain" brands around, they still experience more problems than Hoodman RAW or SanDisk media do. Transcend users are quick to challenge a statement like mine with "used Transcend for many months with no problems", or "never had a problem" but several have found out that buffering problems can occur if files are deleted from the card without formatting before using on the next project. I recommend you use SanDisk or Hoodman RAW. If using SanDisk be sure it is one of the newer cards with UDMA.

December 24th, 2010, 12:49 AM	#4
Jonathan Warren New Boot Join Date: Jul 2008 Location: Springfield, MO Posts: 6	I'll try to do some tests. I have 3 of the Transcend 32 GB cards and I'll fill each one up as much as possible to see if they have problems towards the end of free space. Or if it was just the one, or if it was just a fluke. I'll post my results in the next couple of days. Thanks for the info.

December 25th, 2010, 01:26 AM	#5
Bruce Foreman Trustee Join Date: Nov 2006 Location: San Angelo Texas Posts: 1,518	All those tests will tell you is that at that during the tests you found a problem or had no problem. They will tell you nothing about what lies in store later on. It's not an "absolute" sure thing that you will see problems as you fill the card up. It's simply that the "chances" of the file allocation table not keeping up with where "stuff" goes rise "astronomically" (term used in some articles I've read) the closer you get to filling the media up. It may or may not happen in your tests or it may not happen until the next time you use the card or the 13th time you use it (on a project, of course). SanDisk is not "immune" from the file allocation table error thing, but it does seem to experience somewhat less in the way of problems with that. Nonetheless it is still a good idea to stop at about 75% to 80% card capacity and change to a fresh formatted card. The accounts of Transcend failure I've seen were from people who felt they had no problems in any prior use, but suddenly on a critical project they "lost" data. That's a hard way to find out. Question I asked myself was (even though I'm retired and don't "shoot for hire" anymore), how well could I "afford" failure through not using the best media I could? Most of my "projects" are on a personal level, not really for others and I don't care to take risks by using "bargain" media, and I place Transcend in that category. So I pay the price for SanDisk, bang my head against the wall, and roll on. But I've had no data failures, not even when I got so engrossed I filled a few cards up. Yes, there have been some who experienced problems with SanDisk media. But far fewer than with anything but Hoodman RAW. And I've seen several reports that people who sent a "bad" card back to SanDisk got as a reply, "Uh...Sorry, not one of ours". SanDisk is probably the most counterfeited media out there. Counterfeit copies seem to abound on ebay.

December 25th, 2010, 08:05 AM	#6
Jon Braeley Major Player Join Date: Oct 2007 Location: Miami, FL Posts: 528	I no longer use 32Gb cards and stick with 16Gb and work within these limits. Since doing this I have never had an error, so I think the 32Gb card size is the problem. I've seen many posts from 32Gb card users about errors and corrupted files but very little with 16Gb cards. And most of my 16Gb cards are Transcend with a few SanDisk.