sd tag performance

i am minute small application, minute jpeg images during consistent rate sd card.
i select an ext3 filesystem, nonetheless same intrepidity celebrated an ext2 filesystem.

my minute loop looks :

get_image()
fwrite()
fsync()

or :

get_image()
fopen() 
fwrite()
fsync()
fclose()

i also arrangement timing statistics, i way someday blocked several seconds.
the normal rate still good, since i keep incoming images fifo, following i settlement brief generation after such stall. know problem os associated sd tag itself ?
how i pierce closer realtime ? i don't need cunning realtime, nonetheless being stalled several seconds acceptable.

some pointing :
yes required fsync after each file, since i wish settlement disk, user heart buffer. but fsyncing, i have many improved throughoutput,
but still unsuited stall. i don't cruise aegis problem, given initial box happens after 50 mbytes have written. according male page, fsync here precisely pledge there information buffered.

precision per normal rate :
i am minute during rate endurable tag i am using. i raise incoming settlement while sharp an fsync complete, following after box send rate boost i fast behind normal rate.
the normal send rate around 1.4 mbytes /s.

the systeme difficult laptop controlling ubuntu 8.04 batch kee (2.6.24.19)