CF Card cycles?

[Jim Bridges]

Mike,Dan
So far my Nanoflash has performed flawlessly, it is an absolutely wonderful product.
You have extended the life of my Panasonic HDX900.
This is my first post, so I apologize if this has been covered before.

Any guesses on how the cycles I can get out of my Sandisk Extreme 3 32gb cards before failure? I have 9 of them, and try not keep using the same one over and over again.
I like the feature update of "dual recording" which could minimize this possible problem.

Keep up the great work guys.

Jim Bridges
D.P.
Type A Media
Type A Media, Atlanta, Georgia

[Dan Keaton]

Dear Jim,

It is nice to see you post here on DVInfo.net. We appreciate the kind words about the nanoFlash.

While we write a lot of data to the CompactFlash cards, the number of write cycles is actually very low for each memory cell.

These modern memory cards have wear leveling to prevent the same cells from being used over and over again.

Lets say that you fill up a card on a shoot. This would be about 1 write cycle per memory cell.

Read cycles do not count, as no wear on the card occurs when reading the memory cells.

Then, lets say that you dump the card and reuse it the same day.

Now we are up to two write cycles per memory cell.

Now, lets say that you do this every day for a year. 365 x 2 = 730 write cycles per memory cell.

This is very low for a high quality, well designed CompactFlash card, even if you do this year after year.

In our lab, we are testing our "Loop Recording", 24/7. We have been testing this for some time, over a week, but probably less than two weeks. On Wednesday I was told we had written over 1,000 files to the two cards. No problems at all, so far.

I can not tell exactly, but this may be around 55 write cycles for every memory cell. (1000 / 2 cards / 9 files per card). I know that we are way over 1000 files at this time and I expect us to continue this test for a while.

Now, specifically to answer your question.

With SanDisk cards, I would not worry. I would not worry about any of the brands we recommend. I believe that all of the brands that we recommend have a lifetime warranty, but of course, no one wants to have to use it.

I have heard multiple reports of Kingston cards failing prematurely. We do not recommend Kingston cards.


Contrast this to people using the same technology in Solid State Disks. One can easily run up thousands a write cycles in a very short time. Computers write to the File Allocation Table quite frequently when creating a file. This is very hard on solid state disks.

We took this into consideration when we designed the nanoFlash. We purposely limit the number of times that we write to the File Allocation Table to ensure that we do not have premature CompactFlash card failures.

Jim, I hope this helps.

[Jim Bridges]

Thanks Dan,
This helps a lot. With my Sandisk Extreme 3 32gb cards, I am currently limited to 140 Long GOP, with the current update will I be able to record at 160 Long GOP?

Jim Bridges
D.P.
Type A Media

[Dan Keaton]

Dear Jim,

If you use our latest firmware, 1.1.154, you can record at 180 Mbps using your SanDisk Extreme III cards.