Improving Training Performance and Scalability Documentation (#28497)

* Improving Training Performance and Scaling documentation by adding PEFT techniques to suggestions to reduce memory requirements for training

* Update docs/source/en/perf_train_gpu_one.md
Co-authored-by: Younes Belkada <49240599+younesbelkada@users.noreply.github.com>

---------
Co-authored-by: Younes Belkada <49240599+younesbelkada@users.noreply.github.com>

docs/source/en/perf_train_gpu_one.md

@@ -51,7 +51,8 @@ The methods and tools covered in this guide can be classified based on the effec
 | [Data preloading](#data-preloading)                        | Yes                     | No                           |
 | [DeepSpeed Zero](#deepspeed-zero)                          | No                      | Yes                          |
 | [torch.compile](#using-torchcompile)                       | Yes                     | No                           |
-
+| [Parameter-Efficient Fine Tuning (PEFT)](#peft)            | No                      | Yes                          |
+ 
 <Tip>
 
 Note: when using mixed precision with a small model and a large batch size, there will be some memory savings but with a 
@@ -400,6 +401,25 @@ Choose which backend to use by specifying it via `torch_compile_backend` in the
 
 For an example of using `torch.compile` with 🤗 Transformers, check out this [blog post on fine-tuning a BERT model for Text Classification using the newest PyTorch 2.0 features](https://www.philschmid.de/getting-started-pytorch-2-0-transformers)
 
+## Using 🤗 PEFT
+
+[Parameter-Efficient Fine Tuning (PEFT)](https://huggingface.co/blog/peft) methods freeze the pretrained model parameters during fine-tuning and add a small number of trainable parameters (the adapters) on top of it.
+
+As a result the [memory associated to the optimizer states and gradients](https://huggingface.co/docs/transformers/model_memory_anatomy#anatomy-of-models-memory) are greatly reduced.
+
+For example with a vanilla AdamW, the memory requirement for the optimizer state would be:
+* fp32 copy of parameters: 4 bytes/param
+* Momentum: 4 bytes/param
+* Variance: 4 bytes/param
+
+Suppose a model with 7B parameters and 200 millions parameters injected with [Low Rank Adapters](https://huggingface.co/docs/peft/conceptual_guides/lora).
+
+The memory requirement for the optimizer state of the plain model would be 12 * 7 = 84 GB (assuming 7B trainable parameters).
+
+Adding Lora increases slightly the memory associated to the model weights and substantially decreases memory requirement for the optimizer state to 12 * 0.2 = 2.4GB.
+
+Read more about PEFT and its detailed usage in [the PEFT documentation](https://huggingface.co/docs/peft/) or [PEFT repository](https://github.com/huggingface/peft).
+
 ## Using 🤗 Accelerate
 
 With [🤗 Accelerate](https://huggingface.co/docs/accelerate/index) you can use the above methods while gaining full