What is JIT in a Switch emulator?

JIT (just-in-time compilation) means the emulator translates the Switch game's ARM machine code into code your device can run, while the game is running. Switch emulators depend on it; without JIT you're left with an interpreter that is far too slow, which is why MeloNX on iPhone requires JIT.

What's the difference between shader cache and PPTC?

The shader cache stores graphics shaders compiled for your GPU, which cuts stutter. PPTC is a Ryujinx-family feature that saves translated CPU code to disk to cut load times; it kicks in on the third launch, after the game has reached the title screen twice.

Does Turnip work on MediaTek or Exynos phones?

No. Turnip is Mesa's open-source Vulkan driver for Qualcomm Adreno GPUs and only works on Snapdragon chips with Adreno. Phones with Mali or other GPUs have to use the system driver.

What's the difference between NSP, XCI and NSZ?

NSP is the package format for digital games, updates and DLC. XCI is a full image of a game cartridge. NSZ and XCZ are losslessly compressed NSP and XCI files.

What do docked and handheld mode change in an emulator?

Docked mode emulates a Switch sitting in its TV dock, so games render at a higher resolution and need more power. Handheld mode emulates portable play at a lower resolution. On weaker PCs and phones, handheld mode is a common way to gain speed.

Switch Emulator Glossary: JIT, Shader Cache, PPTC, NCE, Turnip

This is a glossary of common Switch emulator terms, grouped into CPU, graphics, files and keys, mods, console modes, iOS and Android, and releases. There are 50+ entries, each one to three sentences. If a guide uses a word you don't know, Ctrl+F this page. Version-specific details were checked on October 30, 2026.

CPU and performance

Term	Meaning
JIT (just-in-time compilation)	The emulator translates the Switch game's ARM machine code into native code while the game runs. Switch emulators depend on it. iOS blocks it by default and needs a debugger to allow it; see enabling JIT on iOS.
Interpreter	Executes game instructions one by one without generating native code. Very compatible, but far too slow for Switch games.
Dynarmic	The ARM dynamic recompiler (JIT backend) used by yuzu-family emulators such as Eden and Citron Neo. Citron Neo maintains its own GPLv3 branch.
ARMeilleure	The CPU emulator in Ryujinx-family emulators (Ryubing, MeloNX, Kenji-NX). It turns ARM code into an intermediate form and then generates native code.
NCE (Native Code Execution)	On ARM devices, runs the Switch's ARM code directly with no translation. Eden's docs say to always use NCE on Android when it works, because JIT costs a lot of performance.
Hypervisor	On Apple silicon Macs, runs Switch code natively inside a virtualized environment. It's how Ryubing gets its speed on Mac; if a new build crashes, try turning it off.
PPTC (Profiled Persistent Translation Cache)	Ryujinx-family emulators save translated CPU functions to disk, which cuts the time to the title screen a lot. It takes effect from the third launch, after the game has reached the title screen twice.
PGO build	A build optimized with profiling data. Eden says its PGO builds are 10-30% faster.
CPU accuracy	How strictly the emulator emulates the CPU, usually Auto, Accurate or Unsafe. Unsafe is faster but can cause floating-point errors and other issues; start with the default.

Graphics

Term	Meaning
Shader	A small program that runs on the GPU. Every new model or effect in a game means the emulator has to compile its shaders for your GPU.
Shader cache	Stores compiled shaders on disk so they don't have to be compiled again, cutting stutter. It's tied to your GPU and driver version, so it rebuilds after a driver change.
Shader compilation stutter	The hitch when a game pauses to compile a shader it hasn't seen before. The more you play, the fuller the cache and the less it happens.
Pipeline cache	A cache of Vulkan pipeline state that cuts pipeline creation overhead. In Eden it's a separate toggle from the shader cache.
Async shaders	Compiles shaders in the background and skips drawing them for a moment, trading brief missing or wrong graphics for less stutter. Eden has the option; Ryubing has said it won't add it.
Vulkan	A cross-platform, low-overhead graphics API and the preferred backend for Switch emulators. It's the only option on Android, and Citron Neo is Vulkan-only.
OpenGL	An older graphics API kept as a fallback on Windows and Linux. Vulkan compiles shaders much faster.
Metal	Apple's graphics API. Macs and iPhones have no native Vulkan, so everything ends up on Metal; Hydra and nxnative use Metal directly.
MoltenVK	A layer that translates Vulkan calls to Metal. Ryubing and Eden on Mac, and MeloNX on iOS, run through it.
Turnip	Mesa's open-source Vulkan driver for Qualcomm Adreno GPUs. It only works on Snapdragon's Adreno. On Android you load it inside the emulator's GPU driver manager, no root needed; see Turnip drivers on Android.
System driver	The GPU driver that ships with your phone. Eden's docs say it's usually faster on Adreno but less compatible; Mali and other non-Adreno phones can only use it.
Resolution scale	How much the game's native resolution is multiplied, such as 2x. Ryubing recommends 2x for a 1080p display and calls 4x overkill for almost any setup.
ASTC	A texture compression format common in Switch games. PC GPUs don't support it natively, so it must be decoded, which costs time and VRAM. Eden can decode it on the GPU.
Scaling filter	The algorithm used to fit the image to your window or screen, such as Bilinear, FSR or Area. FSR suits upscaling; Area suits downscaling when internal resolution is above your screen's.
Anisotropic filtering	Sharpens textures seen at an angle, like the ground. Eden's docs warn against turning it off, since that breaks graphics in many games.

Files, keys and system

Term	Meaning
NSP	The package format for digital games, updates and DLC.
XCI	A full image of a game cartridge. Untrimmed XCIs include a system update, which Ryubing can use to install firmware.
NSZ / XCZ	Losslessly compressed NSP / XCI files. Support varies by emulator.
NCA	The basic encrypted container for Switch content. NSPs and XCIs hold NCAs, which need keys to open.
NRO	The executable format commonly used by Switch homebrew. Homebrew runs in emulators without keys.
prod.keys	The console's system key file, used to decrypt games and firmware. Required; see prod.keys and firmware explained.
Title key / title.keys	Per-title decryption keys for digital games, updates and DLC, usually dumped together with prod.keys.
Firmware	The Switch system software. Emulators use it for system archives, fonts, Miis, HOME menu data and more. Keep it matched with your keys; keys must be at least as new.
Dump	Copying keys, firmware or games off a Switch console for use in an emulator.
CFW (custom firmware)	Third-party system software run on a hacked console.
Title ID	A game's unique 16-digit hexadecimal ID. Mod and cheat folders are named after it.
Build ID	A unique ID for the main executable of a specific game version. Cheat and code patch file names use it, so they break when the game updates.

Mods and cheats

Term	Meaning
LayeredFS	A way to overlay external files on top of a game's assets without touching the originals. It began as a Switch custom-firmware feature; emulators implement the same idea, and it's the basis of most mods.
RomFS / ExeFS	RomFS is the game's asset partition (textures, models, text, audio). ExeFS is the executable code partition. Mods replace one or the other.
IPS patch	A binary code patch for a specific Build ID. Many 60 FPS patches use this format.
Cheats	Codes that modify game memory, in files named after the matching Build ID. Ryubing disables them all by default and you tick the ones you want; Eden enables them by default.
60 FPS mod	Changes game logic so it runs at 60 FPS at normal speed. Simply unlocking the frame rate usually speeds the whole game up, because most Switch games tie game speed to frame rate.

Console modes and multiplayer

Term	Meaning
Docked mode	Emulates a Switch sitting in its TV dock: higher output resolution, more demanding.
Handheld mode	Emulates portable play: lower resolution, lighter load. A common speed fix on weaker hardware. In Ryubing, unticking "Enable Docked Mode" puts you in handheld mode.
LDN (local wireless)	The Switch's short-range console-to-console wireless play. Emulators tunnel it over the internet so you can play with other emulator users. It doesn't connect to Nintendo's online service.

iOS and Android

Term	Meaning
Sideloading	Installing an app outside the App Store, signed with your own Apple ID. Apps signed with a free Apple ID expire after 7 days. Apple has allowed emulators on the App Store since 2024, but App Store apps can't use JIT, so Switch emulators must be sideloaded.
get-task-allow	The entitlement that lets a debugger attach to an app. Only development-signed (sideloaded) apps have it, and it's a prerequisite for JIT on iOS.
TXM (Trusted Execution Monitor)	A security layer introduced in iOS 26. On A15 or newer iPhones and M2 or newer iPads, JIT memory must first be authorized by a debugger, so only apps updated for it can use JIT.
Pairing file	A file recording the trust relationship between an iPhone and a computer. StikDebug and SideStore use it to enable JIT and refresh apps on the phone itself.
Increased Memory Limit	An iOS app entitlement. MeloNX needs it on every device, and lower-memory iPads and iPhones also need "Extended Virtual Addressing," which requires a paid developer account.
Native port	Instead of emulating hardware, the game's code is rewritten to run directly on the target device. nxnative takes this route and says plainly that it is not an emulator.

Releases and projects

Term	Meaning
Stable / Nightly / Canary	Stable releases are well tested. Nightly (Eden) and Canary (Ryubing) are automatic builds from daily or per-commit changes: newer, but more likely to break.
Portable mode	Keeps config, saves and keys in the program's own folder, which makes backups and side-by-side versions easier. Ryubing uses a `portable` folder; Eden uses a `user` folder.
Fork	A new project built from someone else's open-source code. Eden and Citron Neo are yuzu-family forks; Ryubing and MeloNX are Ryujinx-family forks.
DMCA takedown	A request under the US DMCA asking a platform to remove content. Nintendo had GitHub remove emulator repos many times in 2026, arguing that emulators use prod.keys to decrypt games and so circumvent its protection measures. See Are Switch emulators legal?

Switch Emulator Glossary: JIT, Shader Cache, PPTC, NCE, Turnip and 50+ Terms

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