Menu File– Options – Limits
Maximum board windows
This determines how many board windows may be opened at any one time. When you load a new game ChessBase will automatically replace the previous game when the limit is reached. This helps you keep the desktop manageable.
Maximum database windows
Determines how many list windows can be opened simultaneously. Again ChessBase replaces the last one when the maximum is reached.
Number of recent games
This determines how many recently loaded games should be displayed in the Menu File – Recent games.
Number of recent databases
This determines how many recently loaded databases should be displayed in the Menu File – Recent databases.
RAM
Displays how much memory is available on your system. It refers to installed, not free memory.
Cache for reference database
ChessBase reacts to repeated searches in the reference database by caching (holding) large chunks of the database in memory, making all operations much faster. If you have a lot of RAM (512 MB or more) most of the reference database will be cached. After the first search you will notice that there is no more hard disk activity, and that the search has speeded up by a factor of more than ten.