Move Complete ORACLE from one system to another
If it's the same Oracle version, then it might work. Since the old system had 16GB, both have to be 64bit so that shouldn't be an issue, either.

NOTE You're going to save a few minutes at the risk of introducing a subtle problem in your production system. So unless your data isn't worth the time to do a proper export/import, I wouldn't do it.

Anyway. Make a backup of the data before trying this. Use the exp tool for this. The counterpart imp is able to import the data into a new databse. Incidentally, this is how you should do it in the first place.

If you don't want to make a backup, I suggest to at least make a raw copy of the old disk.

Some things that can go wrong:


Your old hard disk might have a faulty sector which now, you won't notice.
There might already be data corruption in your database.
Oracle might have saved the CPU ID or similar data somewhere in the database as a means of copy protection.