| Option Category | # # CORE PERFORMANCE OPTIONS # |
| Description | This option allows MAME to change the speed of a running system. This is adjusted by a factor of 1. e.g 1.0 = 100% Speed | 0.25 = 25% Speed | 2.5 = 250% Speed. Beside the system speed, this speed factor will affect the sound pitch as well. This option accepts decimal values to two decimal points only. If you use more decimal points, MAME will round the value up. |
| Full Command | -speed <float> |
| Alt. Command | none |
| Reverse Command | none |
| Example | mame64.exe pacman -speed 0.5 |
| mame.ini Command | speed |
| Command Default | 1.0 |
| Argument Format | <float> |