howtospark
Training

Tensor parallelism (TP)

Offload / distributeParallelismReference

Split every layer's matmuls across devices and all-reduce the partials — the workhorse for fitting one model on N GPUs.

On the Spark

How we put GLM-5.2 (753B) on 2 Sparks: TP2 over the 200G RoCE fabric, ~111 GiB/rank of ~114 usable — fits, but only just.

Objective
Offload / distribute
Relieves
CapacityCompute
Format
Intra-layer weight sharding + all-reduce
Granularity
Split each matmul across devices
Lifecycle
PTQ · no gradients
Calibration
No calibration
Compression
None — splits across N devices
Quality
100% — same weights, sharded and recombined exactly
Hardware
Fast, low-latency interconnect (NVLink / RoCE / IB) — all-reduce every layer
Runtimes
vLLMTensorRT-LLMSGLang

A worked Spark recipe for this method hasn't been written yet — it lives here as a reference point in the ontology.