# Number of workers in simulated training

**URL:** <https://discuss.flower.ai/t/number-of-workers-in-simulated-training/98>\
**Category:** Flower Help - Beginners\
**Created:** [February 26, 2024, 11:59am UTC](https://discuss.flower.ai/t/number-of-workers-in-simulated-training/98 "2024-02-26T11:59:25Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![flower](https://dub1.discourse-cdn.com/flex013/user_avatar/discuss.flower.ai/flower/32/17_2.png) [@flower](https://discuss.flower.ai/u/flower)\
**Post date:** [February 26, 2024, 11:59am UTC](https://discuss.flower.ai/t/number-of-workers-in-simulated-training/98/1 "2024-02-26T11:59:25Z")

</div>

_This question was migrated from Github Discussions._

**Original questions:**  
Hi everyone i am using `fl.simulation`. Maybe my question is naive, but i was wondering if there is a way to choose the number of worker when i execute `start_simulation`? becuase i notice wheni run it it spawn only 2 worker. Another question on the simulation it is possible to enabkle the gpu accelerator?

* * *

**Answer 1:**  
Pass `num_clients=n` to `start_simulation()` where ‘n’ is the number of workers you want. Then you can also tweak various parameters in the strategy to configure the clients sampling in each round.

* * *

**Answer 2:**  
The number of workers one will see depends on several factors. Two important ones are:

- `num_clients` (as mentioned in Answer 1)
- `fraction_fit` (in the strategy) - if you, for example, call `start_simulation` with `num_clients=100` and a strategy that has `fraction_fit` set to `0.5` then you should see more workers being created

You could try to reproduce this with the first part of the Flower tutorial: [Flower Intro to FL - Pythorch](https://flower.dev/docs/tutorial/Flower-1-Intro-to-FL-PyTorch.html#Starting-the-training)