SNES Consoles Speed Up Over Time: APU Frequency Rises by 182 Hz After 35 Years

Alan Cecil, a security consultant and the mind behind TASBot, a robot known for its tool-assisted speedruns, recently stumbled upon an intriguing discovery concerning the Super Nintendo. His insights reveal that these classic consoles are running a tad faster due to one of their integral components. Thanks to a detailed report by 404 Media, the culprit appears to be the Sony SPC700 APU, responsible for audio processing on the SNES. Traditionally, this chip operates with a digital signal processing (DSP) rate of 32,000 Hz. However, back in 2007, emulator programmers unearthed an anomaly: the actual rate was slightly higher—around 32,040 Hz. This small adjustment was crucial to keep some games from malfunctioning.

The way the SPC700 works is based on a ceramic resonator that ticks away at 24,576 Hz to establish its frequency. Yet, like all delicate electronics, this resonator isn’t immune to external influences like heat, which can alter its performance.

Earlier this year, in February, Cecil took to Bluesky through the TASBot account, sharing his hypothesis and seeking input from SNES enthusiasts. The data gathered painted a fascinating picture: as these consoles age, the SPC700 chip tends to run even faster. The most significant deviation recorded so far is a frequency of 32,182 Hz. Though this deviation is under 1% from its original setting, it holds enough sway to potentially disrupt game audio and glitch a few titles.

### Why Speedrunners Should Pay Attention to the SPC700’s Increasing Frequency

While the SPC700’s role is confined to managing audio, and logically should not intrude on gameplay—unless you’re operating in silence—speedrunners and similar setups that depend on precision could face hurdles due to altered timing. The reason being, during those fleeting black screen transitions between game levels, the console swiftly processes all needed data—including sound—for the upcoming stage. A quicker data relay from the APU to the CPU, thanks to the higher SPC700 frequency, means shorter loading periods.

This may sound like a win for casual players, but it spells chaos for speedrun records and automated speedrunning bots. Thankfully, the modest boost in performance thanks to the SPC700 doesn’t seem to interfere with human speedrunners’ efforts.

Cecil commented, “We’re still unclear about the long-term effects on extended speedruns. However, it’s evident that it has some influence on the speed of data transfer between the CPU and the APU.”

Conversely, TASBot’s runs could face challenges as they require precision down to the millisecond. Cecil’s on a mission to accumulate more data to understand this phenomenon better. Understanding these aged components is paramount as their behavior over time becomes clearer. It’s also essential if we aim to preserve and accurately emulate the beloved classic games from our childhood.