Information about the SNES CPU Turbo option

July 15, 2019 ยท View on GitHub

This is a speedup hack to help reduce or eliminate the notorious slowdown often present in SNES games.

WARNING

Use of the CPU Turbo function is outside the normal operation of SNES hardware. Undesirable issues will occur if you use this feature in many games. The following list of games is simply a reference of titles that are known to have slowdown in the SNES library, and how they react with this feature enabled.

Ranking

All games are ranked by how well this feature can remove slowdown, along with whether any bugs are observed, and the severity of any bugs encountered.

  • A - Slowdown either completely removed or greatly reduced, with no apparent negative side effects
  • B - Good speed improvements, but minor issues occur which keep the experience from being perfect
  • C - Slight speed improvements at least. Games may have moderate issues that are not game breaking
  • D - Improves performance but has severe issues and should not be used
  • E - No improvement / Game-breaking issues

Honorary Mentions

These are games that show a noticeable improvement from Turbo, though already have superior romhacks or SA-1 patches that do a better job of removing slowdown, generally with less stability concerns. These will be listed at the bottom of each rank.

The CPU Turbo option is not available when an SA-1 rom is loaded, in order to avoid likely conflicts.

Results

A

GameNotesPlayable to Ending Confirmed
GunForce
Mega Man X
Parodius Da! Shinwa kara Owarai eX
Phalanx
Ranma Nibunnoichi - Akanekodan Teki Hihou
Ranma Nibunnoichi - Chougi Ranbu HenX
Star FoxCan be enabled along with SuperFX Turbo for maximum effect. Game runs faster which slightly increases difficulty.X
Star Fox 2Can be enabled along with SuperFX Turbo for maximum effect. Game runs faster which slightly increases difficulty.X
Super Bomberman 3
Super R-Type
Super Star Wars
Thunder Spirits
U.N. Squadron
Honorary Mentions
Gradius III~50% speed improvement compared to SA-1 romhack. SA-1 hack also saves high scores and config.X

B

GameNotesPlayable to Ending Confirmed
Demons CrestSmall row of glitched pixels in the top-right corner of the screen, generally only visible when there is vertical scrolling.
King of DragonsSmall flickering line of pixels at top-right corner of screen, along with a few missing pixels in lower-right corner.
Pocky & RockySmall row of flickering pixels on title screen and on 2nd stage.
R-Type IIIScore area in the bottom-right corner is shifted down one row of pixels and a junk line of pixels is visible at the top of the score area.
Stunt Race FXCan be enabled along with SuperFX Turbo for maximum effect. Game runs faster which increases difficulty. Occasional graphical glitches in first person view.X
Super Castlevania IVMinor graphical issues rarely occur.X
Super Ghouls 'n GhostsA couple minor graphical issues with fullscreen effects, observed when the waves crash down in second half of Stage 1, and the rotating towers section of Stage 3.X
Super MetroidSmall black row of pixels appears in the lower-right corner of the mini-map.
Honorary Mentions
Super Mario WorldRow of glitchy pixels on the bottom of the reserve item box. SA-1 hack is a better experience with no graphical glitches.X

C

GameNotesPlayable to Ending Confirmed
Chester Cheetah: Wild Wild QuestImproves slowdown slightly, but most still remains likely due to poor programming.
F-ZeroVery minor slowdown reduction only noticeable when many cars are on-screen, while repeated collisions occur.X
The Legend of Zelda: A Link to the PastRemoves almost all slowdown. Triforce animation on title screen plays faster than normal. Map screen has a peculiar bug with controls that will change the button layout when it is opened. This also affects the Flute item when selecting where to land on the map. Workaround: Toggle turbo off while map is open, or experiment with buttons until you find correct ones.

D

GameNotesPlayable to Ending Confirmed
Magic SwordRemoves all slowdown from game. No sound unless Turbo is turned on after a stage has already started, and even then it cuts out at beginning of next stage unless it is turned off before previous stage ends.
Secret of ManaHelps with slowdown. Music throughout the game changes dramatically when Turbo is enabled, often very unpleasant.

E

GameNotesPlayable to Ending Confirmed
Contra III: The Alien WarsWill not load if Turbo is enabled. Can be used if you activate this after the game has already started, and does a great job of removing slowdown, especially at bosses. If a level ends while this is enabled, the game will freeze on a black screen.
DOOMNo noticeable speed difference and sound effects break with Turbo enabled, yet music will continue to play.
Top Gear 3000Will not load with Turbo enabled. If enabled after the game is loaded, will freeze to a black screen.