[Elphel-support] writing time to a CF card on a Elphel board

[support-list]

Harry, this is what I suspected - it is internal CF feature, not related to the camera or PC. Kind of a built in "garbage collection" for the flash memory pages (NAND flash has rather complicated rules for erasing and writing data). This dead time may vary for different CF cards depending on the controller chip.
Depending on the frame rate and image quality, this may be still tolerable in the camera if the circular image buffer (currently 19MB) can accommodate > 1.7 sec of your data.

Andrey


---- On Wed, 11 Mar 2015 13:35:34 -0700 Harry Kim<hkim at redzone.com> wrote ---- 

Hi Andrey,


I tried your suggestion.   On my Linux machine, the worst case was 1.7 seconds even when I ran the program with a highest priority while the typical time was 12 msec.

No sure what this means because the worst case is still 100 times slower than the normal speed as with the Elphel board.


Harry


On Wed, Mar 11, 2015 at 3:03 PM, support-list <support-list at support.elphel.com> wrote:
Hello Harry,

Can you try the same program with the CF attached to a regular PC running Linux (to have the same code), not to the camera? 

Andrey











-- 
Best regards,



Harry Kim
Senior Embedded Software EngineerRedZone Robotics Inc.
91 43rd Street, Suite 250
Pittsburgh, PA 15201


office 412-927-3456 or 412-476-8980 x214   cell 412-897-0066
hkim at redzone.com
http://www.redzone.com/










 
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