# Real time factor in Issac sim

**URL:** <https://forums.developer.nvidia.com/t/real-time-factor-in-issac-sim/225784>\
**Category:** Isaac Sim\
**Created:** [August 23, 2022, 8:37am UTC](https://forums.developer.nvidia.com/t/real-time-factor-in-issac-sim/225784 "2022-08-23T08:37:33Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![j.varughese](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@j.varughese](https://forums.developer.nvidia.com/u/j.varughese)\
**Post date:** [August 23, 2022, 8:37am UTC](https://forums.developer.nvidia.com/t/real-time-factor-in-issac-sim/225784/1 "2022-08-23T08:37:33Z")

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How do you find out the speed of the issac sim simulation with respect to real time?

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**Author:** ![j.varughese](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@j.varughese](https://forums.developer.nvidia.com/u/j.varughese)\
**Post date:** [September 15, 2022, 5:59am UTC](https://forums.developer.nvidia.com/t/real-time-factor-in-issac-sim/225784/3 "2022-09-15T05:59:17Z")

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The only way I found so far is to drop an object from 9.8 meters and measure the time manually when it hits the ground!! LOL!! There should be a fat box which tells us the real time factor!

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**Author:** ![Hammad\_M](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/hammad_m/32/14047_2.png) [@Hammad\_M](https://forums.developer.nvidia.com/u/Hammad_M)\
**Post date:** [September 20, 2022, 2:12am UTC](https://forums.developer.nvidia.com/t/real-time-factor-in-issac-sim/225784/4 "2022-09-20T02:12:53Z")

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If the simulation is running via the regular launcher start/isaac-sim.sh then the physics step will adjust itself as best it can to remain realtime. If you are running via python.sh then you can do something like this:

The amount of time that is slept will tell you how much faster than realtime things are running. Provided that the simulation is simple enough to run faster than realtime.

```auto
class SteadyRate:
    """ Maintains the steady cycle rate provided on initialization by adaptively sleeping an amount
    of time to make up the remaining cycle time after work is done.

    Usage:

    rate = SteadyRate(rate_hz=60.)
    while True:
      app.update() # render/app update call here
      rate.sleep() # Sleep for the remaining cycle time.

    """

    def __init__ (self, rate_hz):
        self.rate_hz = rate_hz
        self.dt = 1.0 / rate_hz
        self.last_sleep_end = time.time()

    def sleep(self):
        work_elapse = time.time() - self.last_sleep_end
        sleep_time = self.dt - work_elapse
        if sleep_time > 0.0:
            time.sleep(sleep_time)
        self.last_sleep_end = time.time()

```

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**Author:** ![fzg7919](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@fzg7919](https://forums.developer.nvidia.com/u/fzg7919)\
**Post date:** [February 13, 2023, 6:29am UTC](https://forums.developer.nvidia.com/t/real-time-factor-in-issac-sim/225784/5 "2023-02-13T06:29:41Z")

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I think this way just can lower the time factor ， but not raise the time factor.  
Now I made a robor with two 960x540 cameras in Isaac Sim , the time facto is lower than 0.5 , How should I do to raise the time factor to morn than 1 .  
I think it is very significant if we can accelerate the simulation, but the current time factor of Isaac Sim is always lower than 1 .

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**Author:** ![rthaker](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/rthaker/32/171374_2.png) [@rthaker](https://forums.developer.nvidia.com/u/rthaker)\
**Post date:** [March 7, 2023, 10:36pm UTC](https://forums.developer.nvidia.com/t/real-time-factor-in-issac-sim/225784/6 "2023-03-07T22:36:08Z")

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@fzg7919 , as mentioned in previous message, If you use standalone python workflow it will run as fast as possible. if you use isaac-sim.sh it will be realtime.

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**Author:** ![fzg7919](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@fzg7919](https://forums.developer.nvidia.com/u/fzg7919)\
**Post date:** [March 8, 2023, 3:23am UTC](https://forums.developer.nvidia.com/t/real-time-factor-in-issac-sim/225784/7 "2023-03-08T03:23:56Z")

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Thank you so much !  
But now I want standalone python workflow run more faster ? Is there anyting I can do ?  
I use standalone python workflow to run a robot with two 1080x720 resolution cameras that publishing semantic&rgb&depth ros image at 5hz in warehouse, but the fps is about 20hz. Now I want to increase fps to 40 ~60 ? Is it possible ? I turn off reflections and translucency on RTX , the fps increase to about 25 .

And my machine is 3070Ti. Thanks for you help really !

> [@How to increase Isaacsim fps when using ros camera?](https://forums.developer.nvidia.com/t/how-to-increase-isaacsim-fps-when-using-ros-camera/245058):
>
> I build a robot with two cameras that publishing depth and rgb at 5hz in standalone isaacsim , the camera resolution is 1280x720 . But the fps is really low , about 20 fps . How should I increase isaacsim FPS to 60 ? And profilers shows like that

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**Author:** ![system](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/system/32/68080_2.png) [@system](https://forums.developer.nvidia.com/u/system)\
**Post date:** [April 5, 2024, 3:37pm UTC](https://forums.developer.nvidia.com/t/real-time-factor-in-issac-sim/225784/8 "2024-04-05T15:37:17Z")

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