Hi,
What I read from the document it seems that the 8.2 does use more memory than the previous versions. The documents also seem to suggest that you should not need any additional memory on the ASA unit you are using UNLESS its already at heavy memory use in its current software level. And that would probably be the case only if you have a very large configuration?
You can refer to this document which seems to state the RAM requirements for both pre 8.3 and post 8.3
http://www.cisco.com/c/en/us/products/collateral/security/asa-5500-series-next-generation-firewalls/product_bulletin_c25-586414.html
You can naturally also check the Release Notes for 8.2 software. Though I think even they don't clearly state what the requirement is. So better check how the RAM usage is on your unit.
As you can see from the linked document, if your ASA happened to be licensed only for 10 Users (default Base License) or 50 Users you could actually run 8.3+ software level. Though I have to say that I run a newer software level on my home ASA5505 with 256MB RAM and its constantly at 80-90% level.
Cisco Adaptive Security Appliance Software Version 8.4(5)
Device Manager Version 7.1(2)
Hardware: ASA5505, 256 MB RAM, CPU Geode 500 MHz
Internal ATA Compact Flash, 128MB
ASA# show memory
Free memory: 40562712 bytes (15%)
Used memory: 227872744 bytes (85%)
Hope this helps :)
- Jouni
