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Frequently Asked Questions ​

Here we have some common questions people ask. If you have any questions not listed here, feel free to open an issue.

What is the difference between amd64 and amd64-v3? ​

Quoting from golang/go:

Until Go 1.17, the Go compiler always generated x86 binaries that could be executed by any 64-bit x86 processor.

Go 1.18 introduced 4 architectural levels for AMD64. Each level differs in the set of x86 instructions that the compiler can include in the generated binaries:

  • GOAMD64=v1 (default): The baseline. Exclusively generates instructions that all 64-bit x86 processors can execute.
  • GOAMD64=v2: all v1 instructions, plus CMPXCHG16B, LAHF, SAHF, POPCNT, SSE3, SSE4.1, SSE4.2, SSSE3.
  • GOAMD64=v3: all v2 instructions, plus AVX, AVX2, BMI1, BMI2, F16C, FMA, LZCNT, MOVBE, OSXSAVE.
  • GOAMD64=v4: all v3 instructions, plus AVX512F, AVX512BW, AVX512CD, AVX512DQ, AVX512VL.

Setting, for example, GOAMD64=v3, will allow the Go compiler to use AVX2 instructions in the generated binaries (which may improve performance in some cases); but these binaries will not run on older x86 processors that don't support AVX2.

The Go toolchain may also generate newer instructions, but guarded by dynamic checks to ensure they're only executed on capable processors. For example, with GOAMD64=v1, math/bits.OnesCount will still use the POPCNT instruction if CPUID reports that it's available. Otherwise, it falls back to a generic implementation.

The Go toolchain does not currently generate any AVX512 instructions.

Note that processor is a simplification in this context. In practice, support from the entire system (firmware, hypervisor, kernel) is needed.

Which release should I use for my system? ​

Here are some common systems that people use Clash on, and the recommended release for each of them:

  • NETGEAR WNDR3700v2: mips-hardfloat #846
  • NETGEAR WNDR3800: mips-softfloat #579
  • ASUS RT-AC5300: armv5 #2356
  • MediaTek MT7620A, MT7621A: mipsle-softfloat (#136)
  • mips_24kc: #192

If your device is not listed here, you can check the CPU architecture of your device with uname -m and find the corresponding release in the release page.

List of wontfix ​

The official Clash core project will not implement/fix these things:

The following will be considered implementing when the official Go QUIC library releases.

Proxies work on my local machine, but not on my router or in a container ​

Your system might be out of sync in time. Refer to your platform documentations about time synchronisation - things will break if time is not in sync.

Time complexity of rule matching ​

Refer to this discussion: #422

Clash Premium unable to access Internet ​

You can refer to these relevant discussions:

error: unsupported rule type RULE-SET ​

If you stumbled on this error message:

txt
FATA[0000] Parse config error: Rules[0] [RULE-SET,apple,REJECT] error: unsupported rule type RULE-SET

You're using Clash open-source edition. Rule Providers is currently only available in the Premium core.

DNS Hijack does not work ​

Since tun.auto-route does not intercept LAN traffic, if your system DNS is set to servers in private subnets, DNS hijack will not work. You can either:

  1. Use a non-private DNS server as your system DNS like 1.1.1.1
  2. Or manually set up your system DNS to the Clash DNS (by default, 198.18.0.1)