Retro acceleration: The SNES might be running faster as it ages

WTF?! Old hardware typically slows down over time as newer software becomes less optimized and components degrade with age. However, speedrunners and researchers have discovered the opposite effect on the SNES. While the phenomenon is intriguing, its impact on gameplay remains purely theoretical.

Tinkerers and speedrunners have recently discovered that the audio processors in many aging Super NES consoles are now running at slightly higher clock frequencies. While the difference is currently just a few hundred hertz, research suggests the effect may become more pronounced over time.

Alan "dwangoAC" Cecil, a developer of speedrunning tools, first raised awareness of the anomaly last month. To investigate further, he collected data from over 100 SNES owners using a flash cartridge and a diagnostic ROM. The results indicate minor but consistent speed increases, which may be influenced by heat.

The SNES's SPC700, a secondary CPU that controls the console's Sony audio processor, officially runs at 32 MHz. However, Cecil's study found frequencies reaching up to 32.3 MHz, with evidence suggesting this phenomenon has been gradually intensifying for over two decades.

Third-party documentation from 2003 recorded the SPC700 running at 32.04 MHz, which matched the speed used by SNES emulators in the early 2000s. Cecil notes that the average frequency has since risen to 32.076 MHz. The likely cause is the SPC700's ceramic resonator, which can fluctuate based on temperature.

For most collectors still using aging, yellowed SNES consoles, the effect is minor – potentially causing only a slight change in audio pitch if the processor runs around 200 Hz faster than expected. However, the implications for emulation accuracy and speedrunning remain a topic of debate.

A faster sound processor could save players a few frames each time a game loads audio or other data, potentially shaving fractions of a second off long speedruns and putting longstanding records at risk. While Cecil doubts the effect is significant enough to impact records, variations between consoles could complicate the development of emulation tools striving for perfect accuracy.

Research into the phenomenon is still in its early stages. As more SNES units are analyzed, researchers will likely gain a clearer understanding of its causes and effects. Additionally, uncovering more historical data could determine whether the console is gradually accelerating or if the SPC700 has always operated within these frequency variations due to its low-precision design.