Write speed to CF card vs USB Memory stick

This is very odd. I’m hoping that someone can explain it.

I have a QNX 6.3 based system on an AMPRO lb700 board. The system boots and runs
fine in general. HOWEVER, I do like to write data. I have partitioned the card such that I have a large (400Mb) data partition. When I write my data to this partition it is very slow.

I also tried doing the same thing using the devb-umass and this is significantly faster.

my driver load for the CF card is

devb-eide cam nobios &

I have also tried
devb-eide blk

with similar results.

What are other people’s experiences with writing to CF cards?


I’ve used several CF cards under QNX through an IDE connector and the USB port. Not much difference. The limiting factor seems to be the overall write speed of the CF card. Have you tried another CF card?

The driver load used for a FAT32 formatted CF card is:

devb-eide blk cache=2m,rw eide nobios dos exe=system,fsi=update,vollabel=ignore,lfn=always,sfn=windows &

Yeah, I’ve tried 3 different cards with different speeds. I suspect in your case that
the 2m cache helps out a lot. I don’t have that luxury in my project.

I’ll try some of the other options you have there, but I’m not optimistic.

Thanks for sharing!!

Still getting the same response with trying other options. Very curious!