SOVLED: How to Fix Mouse Lag on 4K Screens

This page provides the master list of the things you need to do to correct mouse lag on 4k screens.

If you have connected your PC to a 4K screen you will often see a subtle but visual notable lag between the time you move your mouse and when the pointer moves on the screen.  Using 4K screens on a computer can make things difficult to control if they are not configured correctly.   You can find that your mouse appears to overshoot your movements and does not respond instantly.

There can be many causes of this problem, but in my case most of it was caused by using the wrong HDMI input on the screen.  I was using a large 4K TV as a computer screen and it just was not responding quickly to my mouse movements.  The solution was to move my video cable to from a standard 30Hz HDMI input to a 60Hz HDMI input.  Take a look at this short video which nicely demonstrates the problem and the solution to mouse lag on 4K.

If your PC is connected to your 4K screen at 60Hz or faster and you still see mouse lag, there are several other items to check:

1. HDMI CABLE: There is a lot of discussion about the various HDMI cable standards.  To clear this off your list, go buy a brand name “High Speed” HDMI 1.4 cable.  See this thread for some details on 4K HDMI and this page for some suggested HDMI 1.4 products.  Note that I have not found this to be a problem but others certainly have.
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2. MOUSE DRIVER: Get the latest mouse driver
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3. VIDEO DRIVER: Get the latest driver for your video card and make sure the video resolution is set to match the resolution of your 4K screen, usually this 3840 2160.
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4. HDMI PORTS: Try connecting to different ports on both your video card and your 4K screen.  As shown in the video make sure you are connecting to at least a 60Hz port on the 4K screen.
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5. MOUSE DPI: Most mice scan the surface at about 800 dots per inch (DPI).  High resolution 4K and even 8K screens will require a mouse that scans more to avoid lag.  There is lots of information online explaining mouse scanning and DPI but it is generally considered truth that beyond about 2500 DPI claims by manufacturers are only backed up by algorithmic gymnastics that do not have much if any positive impact on real life performance.  I found the Logitech G402 and G602 wireless mouse to provide absolutely no lag.
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6. MOUSE SETTINGS: Make sure the mouse is set to scan at the higher resolution.  High DPI mice, like those mentioned in item 5 above, do not always scan at the highest level.  In an effort to save battery, manufacturers will often set a high DPI mice to scan a low DPI during normal use.  This is why some people see that their mouse works fine in games but it is slow in standard Windows use.  Games sometimes result in the DPI being increased automatically.  Go into the driver or the mouse software and set it to 2000 DPI or above.  Also note that some mice, like the G602, have a switch on the top of the mouse that toggles the mouse speed.
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7. USB PORT: Connect the mouse (or mouse receiver) to different USB ports on the PC.  There is talk on the internet of differences between USb3 and USB2 connections and even though I believe this makes no difference to a mouse it is worth trying alternate ports all the same.

If none of these work and you have decided that you are just going to have to live with some lag on your 4K screen, there are a few things you can do to improve your usability even with the lag:

1. Enable ‘Mouse Trails’
2. Set the pointer to be large and using a different colour than the typical background you are using.
3. Learn to move your hand / mouse slower
4. Drink more beer and try not to smash your screen in frustration