先放一个官方无声的视频,本文主要围绕此视频理解zero的原理和实践。 zero的三个阶段Stage 1 p_{os} : 把 优化器状态 分片到每个数据并行的工作进程(每个GPU)下Stage 2 p_{os+g} : 把优化器状态+ 梯度分片到每个数…
3. 使用计算出来的梯度来更新Adam的两个状态值momentum和variance; 对于上述过程中,我们就可以分别把优化器状态、模型参数和梯度将他们切片存在不同的GPU中。 ZeRO-R 这里介绍怎么把一个层的输入给切分。 因为我们输入要完整的输入,才能计算出结果,哪怕你当前gpu只是其中一部分,所以要从其他部分的输入copy过来。 然...
ZeRO(Zero Redundancy Optimizer)是一种去除冗余的分布式数据并行(Data Parallel)方案,分为Stage 1, Stage 2, Stage 3,而Deepspeed就是论文中ZeRO方法的Microsoft官方的工程实现。 ZeRO-Offload为解决由于ZeRO而增加通信数据量的问题,提出将GPU转移到CPU ZeRO-Infinity同样是进行offload,ZeRO-Offload更侧重单卡场景,而ZeR...
Train llm (bloom, llama, baichuan2-7b, chatglm3-6b) with deepspeed pipeline mode. Faster than zero/zero++/fsdp. nlpbloompipelinepytorchdeepspeedllmfull-finetunemodel-parallizationflash-attentionllama2baichuan2-7bchatglm3-6bmixtral-8x7b
I think they are working on ZeRO stage 3 as well. Even more exciting, ZeRO is being integrated into pytorch. Deployment If you found the results shared in this blog post enticing, please proceed here for details on how to use DeepSpeed and FairScale with the transformers Trainer. Y...
deepspeed ZeRO-Inference 可在1-GPU上推理～100B的大模型 原理:
The tests were conducted using 400 NVIDIA V100 GPUs; with more devices (such as 1,000 GPUs), ZeRO-2 allows us to scale toward 200 billion parameters. Speed: Improved memory efficiency powers higher throughput and faster training. Figure 2 (bottom left) shows system throughput of ZeRO-2...
reducing communication cost. ZeRO-2 is also up to 5x faster than ZeRO-1 because its additional memory savings help reduce communication further and support even larger batch sizes. Scalability:We observe superlinear speedup (Figure 2, top right), where the performance more than doub...
ZeRO++ 性能提升 相比于 ZeRO，ZeRO++ 在前向通信中节省一半的跨机通信量，在后向通信中无需跨机通信，梯度同步减少 3/4 的跨机通信量。优化后的通信量分布使得 ZeRO++ 在节点间通信效率得到显著提升。实现优化细节 ZeRO++ 实现优化涉及两个关键点：通信与计算隐藏，以及融合算子优化，旨在最大化带宽...
We offer near-linear scalability both in terms of anincrease in model sizeas well asincrease in number of GPUs. As shown inFigure 3a, together with the DeepSpeedZeRO-3, its novel CPU offloading capabilities, and a high-performance Azure stack powered by InfiniBand Quantum int...