Local AI Advisor

Can Mac Studio M3 Ultra 512 GB run GLM-5.3-Flash (320B-A18B)?

512 GB unified · 819 GB/s memory bandwidth · GLM-5.3-Flash (320B-A18B) has 320B parameters (18B active per token).

Short answer

Yes, excellent for chat and acceptable or better for every workload we test.

Best quantization for chat: 4-bit (169 GB of weights) on LM Studio. Generation: 25–35 tok/s, leaving about 331 GB free for your other apps.

How it rates for each workload

Same model and machine, different jobs. Agents and long documents send far bigger prompts than chat, so they need much more speed and memory.

WorkloadVerdictQuantGenerationFirst replyContext
Chatwith Open WebUIExcellent4-bit25–35 tok/s≈2 s8KDetails
Coding questionswith ContinueExcellent4-bit25–35 tok/s≈10 s16KDetails
Coding in a repositorywith AiderComfortable4-bit25–30 tok/s≈35 s32KDetails
Agentic codingwith OpenCodeAcceptable5-bit19–25 tok/s≈45 s32KDetails
Long documents (64K)with Open WebUIComfortable4-bit25–30 tok/s≈3 min64KDetails

Speeds are estimates calibrated against measured benchmarks on similar hardware. “First reply” is the time to read the workload’s opening prompt. How we calculate

Different tool, context size or workload?

These pages use typical settings. The full check models your exact setup.