Starting with the Solaris 10 3/05 release, you can choose to install the software with a GUI or with or without a windowing environment. If the memory is sufficient, the GUI is displayed by default. If the memory is insufficient for the GUI, other environments are displayed by default. You can override defaults with the nowin or text boot options. However, you are limited by the amount of memory in your system or by installing remotely. Also, if the Solaris installation program does not detect a video adapter, the program is automatically displayed in a console-based environment.
For specific memory requirements, see System Requirements and Recommendations.