At least I think its the culprit.  I'm developing under QNX 6.5.0.  Our system is an x86 PC-104 with 256 MB of RAM.  The
 devb-eide task is consuming 49MB of RAM.  The file system is on a 2GB Compact Flash.  I start the drivers as follows:

devb-eide quiet blk ramdisk=10m cache=2m qnx6 &
waitfor /dev/hd0
mount -t qnx6 -o sync=optional /dev/hd0t177 /

The ramdisk is occupying 10MB of this.  I've tried some of the memory saving tricks documented for io-blk but they did 
not seem to change this value.  I understand the nature of the the power fail safe system might use a lot of RAM, but is
 there any way I can control the RAM usage?