mirror of
https://github.com/oobabooga/text-generation-webui.git
synced 2024-10-31 14:40:15 +01:00
64 lines
2.0 KiB
Markdown
64 lines
2.0 KiB
Markdown
>FlexGen is a high-throughput generation engine for running large language models with limited GPU memory (e.g., a 16GB T4 GPU or a 24GB RTX3090 gaming card!).
|
|
|
|
https://github.com/FMInference/FlexGen
|
|
|
|
## Installation
|
|
|
|
No additional installation steps are necessary. FlexGen is in the `requirements.txt` file for this project.
|
|
|
|
## Converting a model
|
|
|
|
FlexGen only works with the OPT model, and it needs to be converted to numpy format before starting the web UI:
|
|
|
|
```
|
|
python convert-to-flexgen.py models/opt-1.3b/
|
|
```
|
|
|
|
The output will be saved to `models/opt-1.3b-np/`.
|
|
|
|
## Usage
|
|
|
|
The basic command is the following:
|
|
|
|
```
|
|
python server.py --model opt-1.3b --flexgen
|
|
```
|
|
|
|
For large models, the RAM usage may be too high and your computer may freeze. If that happens, you can try this:
|
|
|
|
```
|
|
python server.py --model opt-1.3b --flexgen --compress-weight
|
|
```
|
|
|
|
With this second command, I was able to run both OPT-6.7b and OPT-13B with **2GB VRAM**, and the speed was good in both cases.
|
|
|
|
You can also manually set the offload strategy with
|
|
|
|
```
|
|
python server.py --model opt-1.3b --flexgen --percent 0 100 100 0 100 0
|
|
```
|
|
|
|
where the six numbers after `--percent` are:
|
|
|
|
```
|
|
the percentage of weight on GPU
|
|
the percentage of weight on CPU
|
|
the percentage of attention cache on GPU
|
|
the percentage of attention cache on CPU
|
|
the percentage of activations on GPU
|
|
the percentage of activations on CPU
|
|
```
|
|
|
|
You should typically only change the first two numbers. If their sum is less than 100, the remaining layers will be offloaded to the disk, by default into the `text-generation-webui/cache` folder.
|
|
|
|
## Performance
|
|
|
|
In my experiments with OPT-30B using a RTX 3090 on Linux, I have obtained these results:
|
|
|
|
* `--flexgen --compress-weight --percent 0 100 100 0 100 0`: 0.99 seconds per token.
|
|
* `--flexgen --compress-weight --percent 100 0 100 0 100 0`: 0.765 seconds per token.
|
|
|
|
## Limitations
|
|
|
|
* Only works with the OPT models.
|
|
* Only two generation parameters are available: `temperature` and `do_sample`. |