# Gazebo Multiple Plane SITL

**URL:** <https://discuss.px4.io/t/gazebo-multiple-plane-sitl/20073>\
**Category:** Uncategorized\
**Created:** [December 14, 2020, 7:04am UTC](https://discuss.px4.io/t/gazebo-multiple-plane-sitl/20073 "2020-12-14T07:04:06Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![karanveer.dewan](https://discuss.px4.io/letter_avatar_proxy/v4/letter/k/34f0e0/32.png) [@karanveer.dewan](https://discuss.px4.io/u/karanveer.dewan)\
**Post date:** [December 14, 2020, 7:04am UTC](https://discuss.px4.io/t/gazebo-multiple-plane-sitl/20073/1 "2020-12-14T07:04:06Z")

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Hi folks,

I am facing an issue while using multi-vehicle SITL with Gazebo. The “iris” model works flawlessly even with 10 instances following a mission via QGCS (real time factor close to 1). But while running “plane” or “standard\_vtol” model, even when they are grounded, the simulation speed real time factor drops down to ~0.1 (even at 2 instances), even lesser when adding more instances.

How do I make sure the “plane” model (multiple instances) also works at a real time factor close to 1?

@Jaeyoung-Lim Can you provide some insights? As you seem to have run a multi-plane sim without any frame drop.

TIA