Why SNES hardware is running faster than expected—and why it’s a problem
1 min read
Summary
The Super Nintendo Entertainment System (SNES) is prone to unpredictability in its Audio Processing Unit (APU), which relies on a cheap ceramic resonator that is affected by factors including heat and age.
This means that the APU’s clock can often run faster than the stipulated 24,576 Hz, perceivable only as a slightly higher pitch for in-game music and sounds.
However, the problem is more serious for tool-assisted speedrunners (TAS), who rely on precise frame accuracy to achieve consistent performances.
A TASBot team member, Allan “dwangoAC” Cecil, has traced the problem to the APU, which, if it runs faster than specified, can cause unpredictable “lag frames” that throw off the synchronisation between the TAS inputs and the results achieved on actual hardware.
While the problem has been identified, there is no easy solution, and it could affect any SNES console to some degree.
