Changes

{| class="wikitable" style="text-align:center;"

! scope="col" style="text-align: center;"|System! scope="col" style="text-align: center;"|Normal clock! scope="col" style="text-align: center;"|Hardware Overclock! scope="col" style="text-align: center;"|Emulation Overclock! scope="col" style="text-align: center;"|Overclock levels

| style="text-align: center;"|[[Nintendo Entertainment System emulators|NES]]| style="text-align: center;"|1.79 MHz| style="text-align: center;"|Yes{{✓}}| style="text-align: center;"|Yes{{✓}}| style="text-align: center;"|?

| style="text-align: center;"|[[Super Nintendo emulators|SNES]] (Main CPU)| style="text-align: center;"|3.58 MHz| style="text-align: center;"|Yes{{✓}}| style="text-align: center;"|Yes{{✓}}| style="text-align: center;"|4.1 -7.6 Mhz

| style="text-align: center;"|[[Super Nintendo emulators|SNES]] (Super FX 1)| style="text-align: center;"|10.5 MHz| style="text-align: center;"|Yes{{✓}}| style="text-align: center;"|Yes{{✓}}| style="text-align: center;"|40-60 Mhz

| style="text-align: center;"|[[Super Nintendo emulators|SNES]] (Super FX 2)| style="text-align: center;"|21 MHz| style="text-align: center;"|Yes{{✓}}| style="text-align: center;"|Yes{{✓}}| style="text-align: center;"|40-60 Mhz,

| style="text-align: center;"|[[Sega Genesis emulators|Sega Genesis]]| style="text-align: center;"|7.7 MHz| style="text-align: center;"|Yes{{✓}}<ref name="kyorune">http://kyorune.com/modding/article.php?id=73</ref>| style="text-align: center;"|Yes{{✓}}| style="text-align: center;"|13.1-25.4 MHz<ref name="kyorune"/>

| style="text-align: center;"|[[PlayStation emulators|PlayStation]]| style="text-align: center;"|33.8 MHz| style="text-align: center;"|Yes{{✓}}<ref name="kraut">https://www.youtube.com/watch?v=HapnSOseDfw</ref>| style="text-align: center;"|Yes{{✓}}| style="text-align: center;"|66Mhz<ref name="kraut"/>

| style="text-align: center;"|[[Sega Saturn emulators|Sega Saturn]]| style="text-align: center;"|28.6 MHz*| style="text-align: center;"|No{{✗}}| style="text-align: center;"|No| style="text-align: center;"|-{{✗}}

| style[[Nintendo 64 emulators|Nintendo 64]]|93.75 MHz|{{✓}}<ref name="textn64oc">http://www.gamesx.com/misctech/n64oc.htm</ref>|{{✓}}|125-align: center;187.5 Mhz<ref name="n64oc"/>|-|[[Neo Geo emulators|Neo Geo]]| style="text-align: center;"|12 MHz| style="text-align: center;"|Yes{{✓}}<ref name="neooc">http://www.neo-geo.com/forums/showthread.php?158016-68K-s-guide-to-overclocking-your-Neo-Geo-AES</ref>| style="text-align: center;"|Yes{{✓}}| style="text-align: center;"|14-18 MHz<ref name="neooc"/>|-|[[3DO emulators|3DO]]|12.5 MHz|{{na|text=Unknown}}|{{✓}}|{{na}}

By default [[MAME]] allows you to change the clock speed of the systems it emulates (including consoles) to anything between 50% to 200250% of the original clock speed, the only requirement is that you enable cheats for that game/system.

For an NTSC SNES, the master clock rate is approximate ~21.477 MHz, but the CPU's effective clock rates are ~3.58 MHz, ~2.68 MHz, or ~1.79 MHz. This is because any CPU operation takes 6 master cycles (i.e. 21.477/6 = 3.58) and memory access can take 6, 8, or 12, depending on the area of RAM is accessed. In the case of ROM access, it also depends on whether bit 0 of CPU register 420D is set to 0 (SlowROM, 8) or 1 (FastROM, 6).<ref name="Fullsnes - Nocash SNES No$SNS Specs">http://problemkaputt.de/fullsnes.htm#cpuclockcycles</ref>

Only MAME has an option to change the main CPU frequency, which requires you to enable cheats. MAME SNES emulation is very demanding by default and activating the overclock only makes it worse. It is more stable than the real hardware while overclocked and won't exhibit the same issues, but it is still very unstable especially if you adjust the frequency multiple times. It also does not allow you to go over 200250% clock speed, which isn't enough to fully get rid of slowdowns in some games.

The latest builds standalone version of all [[Snes9x]] and all of the [[libretro ]] cores builds can overclock by reducing the number of emulated CPU/memory access cycles from 6, 8, and 12 to either 4, 5, and 6 (Compatible) or 3, 3, and 3 (Max) respectively. Just for comparison, that means the Max option is effectively 7.16 MHz. Gameplay is not sped up (assuming the game is not in a constant state of some slowdown, to begin with, like Out of This World) and the issues experienced on real hardware are not present, though stability will vary depending on the game and which option you use. Also to note, some games may work better with the Max option rather than Compatible, as appears to be the case for Mega Man X1 which has a bit of graphical corruption under very specific conditions when using the Compatible option, so try both if you encounter issues.

{| class="wikitable" style="text-align:center;"

! scope="col" style="text-align: center;"|Clock speed! scope="col" style="text-align: center;"|Time! scope="col" style="text-align: center;"|Increase

| style="text-align: center;"|Normal| style="text-align: center;"|1'46'02| style="text-align: center&mdash;"|-------

| style="text-align: center;"|50hz50Hz| style="text-align: center;"|1'23'78| style="text-align: center;"|27.711%<ref name="Dragon50hztest"/> 

The latest standalone version of [[Snes9x]], as well as [[RetroArch|Snes9x-Next]] allows for SFX overclocking, as well as and [[higan|bsnes-mercury]], though allows for SFX overclocking. Though in the latter the increase in CPU requirements can be noticeable.

Some emulators like the [[libretro]] port of [[Mupen64Plus]] have an overclocking option called "VI Refresh", and [[1964 ]] UltraFast (a very old fork of 1964) have an option to overclock the CPU.

<pre>* ''A Bug's Life''* ''Aidyn Chronicles - The First Mage''* ''Armorines - Project S.W.A.R.M.''* ''Big Mountain 2000''* ''Carmageddon''* ''Conker's Bad Fur Day''* ''Destruction Derby 64''* ''Disney's Donald Duck - Goin' Quackers / Donald Duck - Quack Attack''* ''Duck Dodgers Starring Daffy Duck / Looney Toons - Duck Dodgers''* ''Earthworm Jim 3D''* ''Extreme-G''* ''Extreme-G XG2''* ''F1 Racing Championship''* ''F-1 Pole Position 64''* ''Gex 3 - Deep Cover Gecko''* ''GoldenEye 007''* ''Hot Wheels Turbo Racing''* ''Human Grand Prix - New Generation''* ''Jet Force Gemini / Star Twins''* ''Jeremy McGrath Supercross 2000''* ''Kobe Bryant's NBA Courtside''* ''Madden Football 64''* ''Madden NFL 99-2002''* ''Mario Kart 64 (Multiplayer and some tracks only)''* ''Milo's Astro Lanes''* ''Monaco Grand Prix - Racing Simulation 2''* ''Monster Truck Madness 64''* ''NASCAR 99/2000''* ''NBA In the Zone 98 / NBA Pro 98''* ''Off Road Challenge''* ''Perfect Dark''* ''Quake II''* ''Racing Simulation 2''* ''Rakuga Kids''* ''Rayman 2 - The Great Escape''* ''Roadsters Trophy''* ''San Francisco Rush - Extreme Racing (Multiplayer only)''* ''San Francisco Rush 2049 (Multiplayer only)''* ''South Park Rally''* ''StarCraft 64''* ''Starshot - Space Circus Fever''* ''Super Robot Spirits''* ''Taz Express''* ''The New Tetris''* ''Tom Clancy's Rainbow Six''* ''Tonic Trouble''* ''Toy Story 2''* ''Transformers - Beast Wars Transmetal''* ''Turok 2 - Seeds of Evil / Violence Killer - Turok New Generation''* ''V-Rally Edition 99''* ''WCW vs. nWo - World Tour''* ''World Cup 98</pre>''

On emulators, [[Duckstation]] allows you to overclock the CPU up to 1000% or 10x. [https://github.com/SonofUgly/PCSX-Reloaded/releases this This modified build] of [[PCSX-Reloaded|PCSX-R]] as well as [http://ngemu.com/threads/pcsxr-pgxp.186369/ this fork] allow for overclocking, though most games will break past 1.5x clock speed. Recent builds of Beetle PSX (the libretro fork of Mednafen's PS1 core) also support overclocking, by way of removing timing penalties instead of increasing clock speed. EPSXe also natively supports overclocking up to 4x. Hydro Thunder benefits a lot from it, running at a constant 30 FPS without any other issues.

[[Final Burn FinalBurn Alpha]] allows for overclocking of Neo Geo games. MAMEUIFX (aka MAME32FX) also allows for overclocking.<ref>http://mame32fx.altervista.org/home.htm</ref> All Neo Geo should run at full speed when overclocked.

Blastem BlastEm and HazeMD also allow for overclocking but neither are really recommended for normal usage.

Standalone [[Phoenix (emulator)|Phoenix]] and standalone Windows version of [[4DO]] allows up to 4.0/400% of the original 3DO clock speed, making some low frame rate titles such as [[wikipedia:Doctor_Hauzer|Doctor Hauzer ]] and [[wikipedia:Killing_Time_(video_game)|Killing Time]] more playable. The Also possible to overclock CPU in [[libretro ]] version of [[4DO does not ]]<ref>https://docs.libretro.com/library/opera/#core-options</ref> in options in core's quick menu after game launch, but only to 2.0x speed, that still may seem slow. The possibility of this function to contain break games (like incorrect physic and unplayable speed) is unknown. ==Nintendo DS== In DSi and 3DS systems, it is possible to run classic DS games at higher clocks by the use of [[nds-bootstrap]]. This hypervisor has the option of running classic DS games in DSi mode, effectively overclocking featuresthe CPU from 67MHz to 133MHz. This change can remove slowdowns and improve framerate in some games, but can add instability in several others.