Digital Cameras Write Speed on SDHC Memory Cards

I recently purchased some Patriot 32GB 10speed SDHC cards for my Canon 60D. I was excited to see some improvements over my current 16GB 4Speed card…   but I was sadly mistaken.

Problem Symptoms

I can only record a few seconds before I get a “Movie recording has been stopped automatically” message. Apparently I’m not the only person experiencing this problem. This may be an issue with the 60D, as it seems that SanDisk & PNY users are experiencing the same issue on their 32GB 10Speed cards.

The problem is intermittent.  When it occurs, you can see the SD write status light on the camera flashing, but then the flashing will temporarily hold.  At this point, you’ll see the buffer bar pop up on the LCD.  Sometimes it will stall here, or continue.  If you are still recording after 4-5 seconds, you’re golden and it should continue on for minutes of recording.

In this thread, a user recommends using a special SD Formatter, which is specifically designed to comply with SD & SDHC standards.  What’s the difference between this and a standard Windows format?  Well, we’re about to find out. According to memin1857’s posting:

Sd cards are flash devices just like ssd’s. By using it (filling it with data) it will get slow by time. Because overwrites to sectors will be slow compared to fresh sectors as sd controller does not know actually which sectors are free when you delete files.
By formatting with the above utility and setting erase: ON it will instruct sd controller to release all charge from all flash cells so future writes will be much faster. (On par the day you bought your sd card)
This is comparable to MANUALLY TRIMMING an SSD.

NOTE: Do not confuse Overwrite ERASE with Flash ERASE. Overwrite ERASE is just overwriting sectors with zeroes so data is not recoverable but may not necessarily make your card faster, a real Flash ERASE is a command sent to the controller and will make your card freshly fast in short time. (discharging all sectors is a quick operation compared to overwriting them with null data) Also do not confuse with quick format. ERASE:ON is what you want for performance. (Smaller, older sd cards OR some sd card reader/controllers may not support real ERASE function, you will be notified by the format tool if this is the case


This may also fix if hardware sectors do not align with logical sectors. This will affect performance.
You may have trouble finding a configuration that can do flash erase.

Conclusion: Formatting with this tool may enhance your sd card performance and there are no negative affects. Worst case senario is you get do benefit.

I tried the SD Formatter, but am having the same results. However, I was unable to get the “Erase” option to work on my Sony VAIO laptop.  This funky movie recording stopping problem seems identical as when I use the Windows formatting.

I am attaching 4 text files which show the resulting recording sessions on the 3 unique Patriot 32GB cards of the same type.

videoSessions_02_cardA.txt    – Repeating test on first card. Attempting to record full 30 second sessions (file sizes greater than 175MB). Red marks auto-stopped recordings.

02/22/2011  09:09 AM       176,652,568 MVI_1156.MOV
02/22/2011  09:10 AM       177,215,652 MVI_1157.MOV
02/22/2011  09:10 AM       178,358,460 MVI_1158.MOV
02/22/2011  09:11 AM       176,667,328 MVI_1159.MOV
02/22/2011  09:11 AM        31,602,912 MVI_1160.MOV
02/22/2011  09:11 AM       178,501,696 MVI_1161.MOV
02/22/2011  09:12 AM        26,168,012 MVI_1162.MOV
02/22/2011  09:12 AM        32,185,552 MVI_1163.MOV
02/22/2011  09:12 AM        31,843,188 MVI_1164.MOV
02/22/2011  09:12 AM        21,323,728 MVI_1165.MOV
02/22/2011  09:12 AM        32,406,284 MVI_1166.MOV
02/22/2011  09:13 AM        32,109,836 MVI_1167.MOV
02/22/2011  09:13 AM        32,208,380 MVI_1168.MOV

02/22/2011  09:13 AM       177,901,300 MVI_1169.MOV

videoSessions_03_cardB.txt    – Testing a unique second card. Attempting to record full 30 second sessions (file sizes greater than 61MB). Red marks auto-stopped recordings.

02/22/2011  09:22 AM        61,924,480 MVI_1192.MOV
02/22/2011  09:23 AM        62,234,256 MVI_1193.MOV
02/22/2011  09:23 AM        62,047,496 MVI_1194.MOV
02/22/2011  09:23 AM        62,473,264 MVI_1195.MOV
02/22/2011  09:23 AM        26,144,048 MVI_1196.MOV
02/22/2011  09:23 AM        32,028,496 MVI_1197.MOV
02/22/2011  09:24 AM        32,117,764 MVI_1198.MOV

02/22/2011  09:24 AM        62,037,244 MVI_1199.MOV
02/22/2011  09:24 AM        26,262,360 MVI_1200.MOV
02/22/2011  09:24 AM        32,228,560 MVI_1201.MOV
02/22/2011  09:24 AM        32,203,492 MVI_1202.MOV
02/22/2011  09:24 AM        32,324,280 MVI_1203.MOV

videoSessions_04_cardC.txt    – Testing a third card. Attempting to record full 10 second sessions (file sizes greater than 58MB). Red marks auto-stopped recordings. Lens cap was on during these sessions.

02/22/2011  09:36 AM        58,113,676 MVI_1228.MOV
02/22/2011  09:36 AM        60,127,292 MVI_1229.MOV
02/22/2011  09:36 AM        60,470,144 MVI_1230.MOV
02/22/2011  09:36 AM        60,958,272 MVI_1231.MOV
02/22/2011  09:36 AM        31,874,880 MVI_1232.MOV
02/22/2011  09:37 AM        61,413,000 MVI_1233.MOV
02/22/2011  09:37 AM        26,051,140 MVI_1234.MOV
02/22/2011  09:37 AM        31,969,860 MVI_1235.MOV
02/22/2011  09:37 AM        31,953,048 MVI_1236.MOV

02/22/2011  09:37 AM        62,914,432 MVI_1237.MOV
02/22/2011  09:37 AM        62,286,076 MVI_1238.MOV
02/22/2011  09:38 AM        25,760,912 MVI_1239.MOV
02/22/2011  09:38 AM        61,450,564 MVI_1240.MOV
02/22/2011  09:38 AM        26,067,636 MVI_1241.MOV
02/22/2011  09:38 AM        31,970,588 MVI_1242.MOV
02/22/2011  09:38 AM        31,785,792 MVI_1243.MOV

02/22/2011  09:38 AM        60,489,452 MVI_1244.MOV

I find it interesting how, on a freshly formatted card, I’m able to record exactly 4 full sessions. On the fifth session, the recording stops recording automatically after 4-5 seconds.  After 5 sessions, I start to get intermittent failing sessions.

Another detail that I should note: On successful recording sessions that follow a failed session, the buffer bar will pop up and display 2 bars before the bar disappears and the session continues to record as normal. This behavior is consistent on recordings that follow a failed recording session.

My Advice

First, avoid 32 GB cards if you have a Canon 60D. If you have already purchased a few cards (like myself), make sure you have some freshly formatted cards on hand. When the time comes to records some critical moments, just pop in a fresh card and you should get a few good recording sessions before things start failing.

If anyone has better luck with this, please let me know.

In the comments Henry Levenson wrote,

The issue with the movie stopping automatically with the 60D has to due with the buffer capacity of the SD card used and the info transfer rate which has to be equal or > than 40 MB/second. If the transfer rate is slower or the buffer capacity for video’s on the card is exceeded.

If this is true, it leaves me wondering just how useful the speed rating of the card is. Henry’s explanation will potentially disappoint many 32GB SD card owners.
Thanks Henry!


  1. Thanks for the writeup and the links to my post on dpreview.

  2. Jer

    2011/02/21 at 5:41 pm

    My pleasure. I only hope this results in some productive action. Situations like this are difficult because both parties traditionally resort to pointing the finger at the other when it comes to incompatibilities. Currently I’m sitting on over $200 worth of memory that’s half usable. I just hope this issue won’t cause me to miss any critical moments while in Morocco. :\

  3. Jer

    2011/02/22 at 2:10 pm

    I have updated the post due to new data and corrected details (my cards are Patriots, not PNY cards). This means that this issue is appearing on 3 different manufacturer cards. Oh boy.

  4. Jer,

    The issue with the movie stopping automatically with the 60D has to due with the buffer capacity of the SD card used and the info transfer rate which has to be equal or > than 40 MB/second. If the transfer rate is slower or the buffer capacity for video’s on the card is exceeded. The error message above appears. I called Canon technical support about this.
    However, I am still not knowledgeable about clearing the video buffer so more videos can be made.


  5. Jer

    2011/03/03 at 11:42 am

    Ah! That would make sense. The next step is to find out exactly what the buffer size is? Thank you for making sense of this mildly frustrating situation. Luckily, my 16GB card is actually working for me… and if I need to make long videos, the problematic 32GB cards seem to work just fine for the first few videos, on a newly formatted card.

  6. I have recently bought a PNY for my Canon 600D & I am getting the same issue.
    I’m not quiet sure which is slower, the cam or the card however If I turn of the audio recording it seems to be working better.

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