The Alpha edition of Visual C++ provides four basic levels of optimization:
| Option | Description |
| /Od | Perform no optimization. |
| /O1 or /Os | Perform all optimizations that are consistent with keeping the resulting code small. |
| /O2 or /O | Perform all speed optimizations. This option implies /Ob3 and /Oi, but you can override these defaults. |
| /Ox | Perform optimizations that favor speed over code size. This option implies /Ob3 and /Oi, but you can override these defaults. |
If you do not specify an optimization option, the default is /Ox, which includes /Gf, /Gy, /Ob3, and /Oi.
Note If you are porting a project from the x86 platform, see the Reset Project Options topic in Chapter 2 for a discussion of cross-platform optimization issues.