Application memory use

[Michael Hall]

I am noticing what seems to be some memory issues running my application on openjdk versus on Java 6.
Currently in Activity monitor it shows 140.2 MB real mem versus 70.6 for a 1.6 version of the application
It has fairly consistently seemed to be showing that it's using twice as much memory.

I started up jconsole. (With 1.6 , the 1.7 doesn't appear to work? seems to just show a truncated duke image??)
The 1.6 appeared to sawtooth memory in a range, 1.7 seems to climb steady with very infrequent drops.
The current information that jconsole shows.

1.6
Used: 17,248 KB
Committed: 21,968 KB
Max: 253,440 KB
GC time 1.978 sec on MarkSweepCompact(8 collections)
                2.808 sec on Copy (85 collections)

1.7
Used 70,773 KB
Committed 120,384 KB
Max: 233,024 KB
GC time 8.138 sec on PS Scavenge (68 collections)
               2.141 sec on PS MarkSweep(6 collections)

Are there any concerns or things developers should be aware of in this area?