Thanks for the suggestion.
I applied the changes you suggested, hit save/apply and even rebooted the shield. No improvement on the speed test. the output setting was at 1M before the change.
output alert_fast: alert.fast 64k
# output log_tcpdump: tcpdump.log
include classification.config
include reference.config
include reference.config
include $RULE_PATH/local.rules
include $RULE_PATH/snort.rules
#include $PREPROC_RULE_PATH/preprocessor.rules
#include $PREPROC_RULE_PATH/decoder.rules
#include $PREPROC_RULE_PATH/sensitive-data.rules
# include $SO_RULE_PATH/so1.rules
# include $SO_RULE_PATH/so2-misc.rules
Shield v1.51 SP1 + Hotfix Mar 9 Bridge mode