SynergyScale: Optimizing Offloading and Task Partitioning for Efficient Model Training

Abstract

Deep neural networks (DNNs) with billions of parameters power many important applications, but their training is fundamentally constrained by the limited on-chip memory of GPUs. This memory wall forces training to rely on distributed execution or memory offloading, both of which introduce substantial inefficiencies. Existing offloading techniques can scale model size but often incur severe throughput degradation, while conventional distributed training suffers from poor hardware utilization due to limited cross-device bandwidth, leaving accelerator resources underused. We present SynergyScale, a software framework that addresses the GPU memory wall by jointly optimizing memory usage and computation efficiency. SynergyScale combines dynamic hierarchical memory offloading across GPUs, CPU, and secondary storage tiers to reduce GPU memory pressure with fine-grained multi-stream task partitioning that takes advantage of the concurrent execution capabilities of modern GPUs. The framework automatically selects offloading parameters that balance data movement overhead with parallel execution efficiency. Experimental results show that SynergyScale can train a 114.41B-parameter model on a single 80 GB NVIDIA A100 GPU and a 547.77B-parameter model on eight A100 GPUs, supporting models up to 29.5× larger than those enabled by existing approaches. By co-optimizing offloading and computation, SynergyScale achieves up to 4.5× higher training throughput than offloading-only methods, without altering training semantics, making billion-scale model training both efficient and cost-effective.