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terrajobst/RyuJIT-Instructions.md

Last active April 26, 2020 04:06
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RyuJIT-Instructions.md

Try RyuJIT -- Your code runs faster on X64 Windows

How to enable RyuJIT

Download and install RyuJIT now.

RyuJIT only works on 64-bit editions of Windows 8.1 or Windows Server 2012 R2. It will support a larger set of Windows OSes at release

After installation, there are two ways to turn on RyuJIT. If you just want to enable RyuJIT for one application, set an environment variable:

COMPLUS_AltJit="*"

If you want to enable RyuJIT for your entire machine, set the registry key:

HKLM\SOFTWARE\Microsoft\.NETFramework\AltJit
Default (string) = "*"

Both registration methods cause the 64-bit CLR to use RyuJIT instead of JIT64. You can remove these settings at any time and you'll return to using the regular JIT64.

Known Gotchas

  1. No NGen Support. RyuJIT doesn’t change NGen on your system—we wanted to keep the CTP install clean
  2. No Edit & Continue. If you enable RyuJIT while writing code, you’ll find that Edit & Continue doesn’t work on 64-bit. One work around is disable RyuJIT while debugging.

Contact a Human

If you have questions or problems contact us at [email protected].

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