Official specs from Steam

Grand Theft Auto: Vice City system requirements

Minimum and recommended PC specs as listed by the developer on Steam.

Minimum

OS *Microsoft® Windows® 2000/XP
Processor800 MHz Intel Pentium III or 800 MHz AMD Athlon or 1.2GHz Intel Celeron or 1.2 GHz AMD Duron processor
Memory128 MB of RAM
Graphics32 MB video card with DirectX 9.0 compatible drivers ("GeForce" or better)
DirectX VersionMicrosoft DirectX® 9.0
Hard Drive915 MB of free hard disk space (+ 635 MB if video card does NOT support DirectX Texture Compression)
Sound CardSound Card with DirectX 9.0
ProcessorIntel Pentium IV or AMD Athlon XP processor 256(+) MB of RAM
Memory1.55 GB of free hard disk space(+ 635 MB if video card does NOT support DirectX Texture Compression)
Graphics64(+) MB video card with DirectX 9.0 compatible drivers ("GeForce 3" / "Radeon 8500" or better with DirectX Texture Compression support)

FAQ

What graphics card do I need for Grand Theft Auto: Vice City?

Minimum: 32 MB video card with DirectX 9.0 compatible drivers ("GeForce" or better).

How much RAM does Grand Theft Auto: Vice City need?

Grand Theft Auto: Vice City needs 128 MB of RAM at minimum.

How big is Grand Theft Auto: Vice City?

Grand Theft Auto: Vice City requires 915 MB of free hard disk space (+ 635 MB if video card does NOT support DirectX Texture Compression).

Does Grand Theft Auto: Vice City run on Mac or Steam Deck/Linux?

There is no native macOS version. There is no native Linux build (Proton compatibility may vary).