Show HN: Is It Snappy? – Measure latency with your iPhone's 240 Hz camera

Re:Show HN: Is It Snappy? – Measure latency with your iPhone... by swinglock on Monday April 03, 2017 @03:57PM (#14026538)

On the Windows 10 performance, I did a single test and found something mildly interesting.

I tested in Notepad and have the "Hide pointer while typing" setting enabled, and found the first thing that happens on screen is the pointing becoming hidden. That happens after 50 ms. The character shows up in Notepad 16.7 ms later.

This was measured with a 120 FPS camera and an old 60 Hz monitor.

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Re:Show HN: Is It Snappy? – Measure latency with your iPhone... by jesperhh on Monday April 03, 2017 @04:09PM (#14026647)

This is likely because the gpu has specific hardware for drawing the cursor on top of the current framebuffer, which can be turned off quicker than the character can be drawn to the framebuffer

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Re:Show HN: Is It Snappy? – Measure latency with your iPhone... by swinglock on Monday April 03, 2017 @05:53PM (#14027553)

Indeed it does. When using f.lux the color temperature of the cursor remains unchanged due to this.

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Re:Show HN: Is It Snappy? – Measure latency with your iPhone... by kevingadd on Monday April 03, 2017 @11:46PM (#14029314)

You can also observe it in many cases while dragging a window - the composited window's position will lag behind the position of the cursor.

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