使用fp8 后微调速度特别慢

[lhtpluto]

finetune_moss.py 中修改如下
accelerator = Accelerator(mixed_precision='fp8')

环境用的nvidia的容器 nvcr.io/nvidia/pytorch:23.06-py3
https://catalog.ngc.nvidia.com/orgs/nvidia/containers/pytorch

因计算卡显存不足，DeepSpeed offload cpu

修改 sft.yaml 如下

command_file: null
commands: null
compute_environment: LOCAL_MACHINE
deepspeed_config:
gradient_accumulation_steps: 1
gradient_clipping: 1.0
offload_optimizer_device: cpu
offload_param_device: cpu
zero3_init_flag: true
zero3_save_16bit_model: true
zero_stage: 3
distributed_type: DEEPSPEED
downcast_bf16: 'no'
dynamo_backend: 'NO'
fsdp_config: {}
gpu_ids: null
machine_rank: 0
main_process_ip: null
main_process_port: null
main_training_function: main
megatron_lm_config: {}
mixed_precision: fp8
num_machines: 1
num_processes: 1
rdzv_backend: static
same_network: true
tpu_name: null
tpu_zone: null
use_cpu: false

我设置fp8格式微调后，训练速度变慢，是怎么回事呢？

DeepSpeed v0.9.5
FP8 unittest for H100 by @jomayeri in microsoft/DeepSpeed#3731

难道是DeepSpeed offload cpu 后，cpu不支持fp8导致的？ 我的cpu是Intel® Xeon® w9-3495X Processor