GLM-5.3-Flash and Qwen3.8-Flash-Next: what fits on a desk
What running 320B and 180B-class multimodal open weights means for local DGX Spark and workstation hardware.
Both models shipped open weights on August 26, 2026. GLM-5.3-Flash is Z.ai's 320B total / 18B active MoE, natively multimodal, 1M context, MIT license. Qwen3.8-Flash-Next is Alibaba's 125B backbone plus a 51B n-gram table, 6B active per token, natively multimodal, 262K native context extensible to 1M, Qwen Community License 1.0.
The desk question
Neither runs at full precision on a single DGX Spark. GLM-5.3-Flash official FP8 is about 331GB. Qwen3.8-Flash-Next FP8 is about 173GB, with 4-bit quants around 93 to 111GB and the 51B n-gram table designed to offload to host memory.
Where each fits in our hardware paths
Qwen3.8-Flash-Next low-bit quant with n-gram offload is the realistic single-Spark candidate (quantized derivatives only, same rule we apply to every model). Its 4-bit path and GLM-5.3-Flash NVFP4 class quant land on dual Spark.
GLM-5.3-Flash official FP8 belongs on quad Spark or a private cluster. GLM-5.3-Flash's hybrid attention shrinks the KV cache 4.4x, which is what makes 1M-context serving realistic on-prem at all.
License note for Qwen3.8-Flash-Next
It is not Apache 2.0. Commercial use is permitted, but businesses at scale or running model-as-a-service should confirm fit, and we check this during the assessment.
Testing on your workload
We have not published measured throughput for either model yet; trial sessions measure it. The only published measured reference remains Qwen3.8-27B NVFP4 at approximately 86 tok/s.