whisper.cpp fails to initialize Metal on M5 Mac

[richwaters]

On my M5 Mac (macOS 26.4, latest Xcode), the tensor API f16 test fails with "Compiler failed to build request":

ggml_metal_device_init: testing tensor API for f16 support
Compiler failed to build request
ggml_metal_library_init_from_source: error compiling source
ggml_metal_device_init: - the tensor API is not supported in this environment - disabling
ggml_metal_device_init: GPU family: MTLGPUFamilyApple10 (1010)
ggml_metal_device_init: GPU family: MTLGPUFamilyMetal4 (5002)
ggml_metal_device_init: has bfloat = true
ggml_metal_device_init: has tensor = false
ggml_metal_init: found device: Apple M5 Max

I can work around the issue setting GGML_METAL_TENSOR_DISABLE=1.

Environment:

• whisper.cpp v1.8.4
• macOS 26.4
• Xcode 26.4
• Hardware: Apple M5 Max

[nilokmiss-max]

Thank you for reporting this issue with the M5 Max.

…

On Wed, Mar 25, 2026, 11:14 PM Rich Waters ***@***.***> wrote: *richwaters* created an issue (ggml-org/whisper.cpp#3722) <#3722> On my M5 Mac (macOS 26.4, latest Xcode), the tensor API f16 test fails with "Compiler failed to build request": ggml_metal_device_init: testing tensor API for f16 support Compiler failed to build request ggml_metal_library_init_from_source: error compiling source ggml_metal_device_init: - the tensor API is not supported in this environment - disabling ggml_metal_device_init: GPU family: MTLGPUFamilyApple10 (1010) ggml_metal_device_init: GPU family: MTLGPUFamilyMetal4 (5002) ggml_metal_device_init: has bfloat = true ggml_metal_device_init: has tensor = false ggml_metal_init: found device: Apple M5 Max I can work around the issue setting GGML_METAL_TENSOR_DISABLE=1. *Environment:* - whisper.cpp v1.8.4 - macOS 26.4 - Xcode 26.4 - Hardware: Apple M5 Max — Reply to this email directly, view it on GitHub <#3722?email_source=notifications&email_token=B7VEKIWYAE3RGMT77QINDMD4SSVDNA5CNFSL4Z3JMQ5C6L3HNF2C22DVMIXUS43TOVSS6NBRGQYDIMBUG44DNJTSMVQXG33OVJZXKYTTMNZGSYTFMSSWK5TFNZ2KYZTPN52GK4S7MNWGSY3L>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/B7VEKIWBFRDQIRZ6W6TGU5L4SSVDNAVCNFSM6AAAAACW7ZSCSCVHI2DSMVQWIX3LMV43ASLTON2WKOZUGE2DANBQGQ3TQNQ> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[manal617]

Thank you for reporting this issue On Thu, Mar 26, 2026, 4:33 AM nilokmiss-max ***@***.***> wrote:

…

*nilokmiss-max* left a comment (ggml-org/whisper.cpp#3722) <#3722 (comment)> Thank you for reporting this issue with the M5 Max. On Wed, Mar 25, 2026, 11:14 PM Rich Waters ***@***.***> wrote: > *richwaters* created an issue (ggml-org/whisper.cpp#3722) > <#3722> > > On my M5 Mac (macOS 26.4, latest Xcode), the tensor API f16 test fails > with "Compiler failed to build request": > > ggml_metal_device_init: testing tensor API for f16 support > Compiler failed to build request > ggml_metal_library_init_from_source: error compiling source > ggml_metal_device_init: - the tensor API is not supported in this > environment - disabling > ggml_metal_device_init: GPU family: MTLGPUFamilyApple10 (1010) > ggml_metal_device_init: GPU family: MTLGPUFamilyMetal4 (5002) > ggml_metal_device_init: has bfloat = true > ggml_metal_device_init: has tensor = false > ggml_metal_init: found device: Apple M5 Max > > I can work around the issue setting GGML_METAL_TENSOR_DISABLE=1. > > *Environment:* > > - whisper.cpp v1.8.4 > - macOS 26.4 > - Xcode 26.4 > - Hardware: Apple M5 Max > > — > Reply to this email directly, view it on GitHub > < #3722?email_source=notifications&email_token=B7VEKIWYAE3RGMT77QINDMD4SSVDNA5CNFSL4Z3JMQ5C6L3HNF2C22DVMIXUS43TOVSS6NBRGQYDIMBUG44DNJTSMVQXG33OVJZXKYTTMNZGSYTFMSSWK5TFNZ2KYZTPN52GK4S7MNWGSY3L>, > or unsubscribe > < https://github.com/notifications/unsubscribe-auth/B7VEKIWBFRDQIRZ6W6TGU5L4SSVDNAVCNFSM6AAAAACW7ZSCSCVHI2DSMVQWIX3LMV43ASLTON2WKOZUGE2DANBQGQ3TQNQ> > . > You are receiving this because you are subscribed to this thread.Message > ID: ***@***.***> > — Reply to this email directly, view it on GitHub <#3722?email_source=notifications&email_token=B7BDX4OU5MDMGJA4Y3TL5M34ST2QFA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIMJTGMYDMNBSGMY2M4TFMFZW63VKON2WE43DOJUWEZLEUVSXMZLOOSWGM33PORSXEX3DNRUWG2Y#issuecomment-4133064231>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/B7BDX4P67Z2U4R7YO3CRKTD4ST2QFAVCNFSM6AAAAACW7ZSCSCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHM2DCMZTGA3DIMRTGE> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>