Outdated Patch
You should always patch your game to the latest version released by the publisher. The first patch, version 1.1, fixes an issue with corrupted graphics. A later patch, version 2.1, fixes this and other corruptions and bug issues that may cause jumpy performance.
System Requirements
"Grand Theft Auto: Vice City" requires your computer to have certain specifications to run at optimal settings. You should have a processor operating at a minimum speed of 800 MHz and at least 128 megabytes of RAM. These requirements are the absolute minimum the game requires, and you may need a higher-end machine in order to run higher graphics and experience performance.
Graphics Card
While an integrated graphics card may run the game, a dedicated card focuses solely on the game and allows the other memory in your system to run the operating system and other programs or processes. If you purchase a NVIDIA card, it should be series three or better; if you're using ATI Radeon, you should run at least an 8500.
Background Processes
Running a game with high graphics settings uses more system resources, including processing power and memory. You may experience performance issues if you have other programs running in the background that are also consuming resources, such as another game, a Web browser or a Java applet.