# What is a Global Refresh Rate

**URL:** https://discourse.psychopy.org/t/what-is-a-global-refresh-rate/26008
**Category:** Coding
**Tags:** timing, screen
**Created:** [November 16, 2021, 1:48am UTC](https://discourse.psychopy.org/t/what-is-a-global-refresh-rate/26008 "2021-11-16T01:48:11Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![Wjpmitchell3](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/wjpmitchell3/32/33648_2.png) [@Wjpmitchell3](https://discourse.psychopy.org/u/Wjpmitchell3)
#### Post date: [November 16, 2021, 1:48am UTC](https://discourse.psychopy.org/t/what-is-a-global-refresh-rate/26008/1 "2021-11-16T01:48:11Z")

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I’m reading through someone else’s code and there’s a portion I don’t get. I think it’s probably fairly standard because I’ve seen it pop up in other code, but I can’t find an explanation. For reference, win refers to our experiment window:

```auto
    introClock = core.Clock()
    introClock.reset(-_timeToFirstFrame)
    while continueRoutine:
        t = introClock.getTime()
        tThisFlip = win.getFutureFlipTime(clock=introClock)
        tThisFlipGlobal = win.getFutureFlipTime(clock=None)

```

I think I get that nThisFlip represents the expected time of the next screen refresh based upon the introClock. What is a global screen refresh and why is it not tied to a particular clock? I’m inclined to think the fresh rate not just of the window, but the screen, but that doesn’t seem to make sense given that it’s a property of the win object.