Lowering Lag / Latency

If a connected client has poor quality, lag or latency issues, here's how you can find out what causes it and how to resolve it (if possible). At the bottom of the page are suggested solutions.

Check latency numbers in the Parsec overlay

Have something visually active on the host (such as a video or game) to get useful numbers. On the client, click the overlay button at the top-left or press Ctrl+Shift+M to see the information at the bottom.

  • Decode (on the client) and Encode (on the host) is the time either device takes to handle a single frame. If combining decode and encode goes above 16ms, it can cause some bigger issues so avoid at all costs
  • Network is the internet connection ping between the client and host. Below 30ms is a good amount, but below 60ms is still fine for most people

At 60 frames per second, 1 frame is around 16ms. By combining decode, encode and network, you'll have the amount of frames the client lags behind.

Check the Parsec console for network issues

Have something visually active on the host (such as a video or game) to get useful logs. Then access the console and look at the N:0/0/0 numbers.

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If they're far from 0/0/0, it indicates the connection between the client and host is suffering some issues.

Check the internet speed of the host and client

Go to Speedtest to check.

The following is the bare minimum each person needs if they're aiming for good quality at 720p60fps. It uses around 5mbps for the stream (replace with 10 for 1080p60fps):

  • The host needs:
    • 5mbps of upload per client (for sending the stream), with at least 5mbps remaining for other apps to use
    • 2mbps of download per client (for receiving controller inputs)
  • The client needs:
    • 5mbps of download (for receiving the stream), with at least 5mbps remaining for other apps
    • 2mbps of upload (for sending controller inputs)

If either side doesn't have the needed amount, they'll need to upgrade their internet.

Solving issues

Reduce bandwidth, resolution and FPS

You or your client's setup might not be able to handle too much of a high bandwidth, resolution or FPS. Try to reduce everything to the very minimum (bandwidth to 5mbps, resolution to 1280x720, FPS to 60 or 30), and see if the lag or latency is gone. Then move it up little by little and see where you can go until it's too much.

The resolution and bandwidth can be changed in Settings > Hosting. The FPS can be changed if you tweak your screen's refresh rate, or go to Settings > Hosting > Open Configuration File and add the line encoder_fps=number (requires a Parsec restart to update).

Switch the client renderer between OpenGL/DirectX

Clients might have better luck with a different renderer in Settings > Client > Renderer.

Most Windows clients will have a better time with DirectX, and Intel HD Graphics 4000 and older do not support OpenGL well.

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Don't use full screen in applications

If you're experiencing lag only in specific applications or games, this is usually caused by the application being run in full screen. You should change it to run in borderless windowed or windowed mode. If that's not possible, at least turn vsync on for that specific app.

This issue stems from how full screen games render.

Turn off VSync in Parsec and the game

Clients can disable VSync in Settings > Client > VSync, while the host can disable it in the game settings.

Hosts should keep VSync on if they're playing a game in fullscreen, fullscreen games have a tendency to not give Parsec any room otherwise.

Avoid 2.4ghz Wi-Fi, signal boosters and others

Use an Ethernet cable or ensure you're using 5ghz Wi-Fi. Avoid signal boosters, Ethernet over power line or mesh Wi-Fi systems. Move closer to your Wi-Fi if possible.

If you're using Google Mesh, it isn't recommended, but you can eliminate lag by setting the device hosting the Parsec session as the Priority Device on the network.

Mac: Use Zero-Copy Decoding

If you're on a Mac, you can set decoder_zero_copy=1 in Settings > Client > Open Configuration File. Learn more here.

Close unnecessary background applications

Get rid of any background applications that might be stealing resources from Parsec and making it slower.

Keep the same refresh rate between the host and client

If the host and client have differing refresh rates, it might result in what looks like stutter. On the client, go to Settings > Client > Open Configuration File and set server_refresh_rate=60 to force the host to use 60FPS.

Remove any advanced quality settings

If you happen to have experimented around with quality settings in Settings > Client/Hosting > Open Configuration File, remove them to see if it fixes your issues.

Replace your router if it has an Intel Puma chip

If you see a lot of retransmit issues in the Parsec console, find the models of your router and look them up on wikidevi. If yours has the Puma chip in it, you should look to replace it, as these chips do not handle intensive network tasks very well and often cause severe stream issues.

I'm still having issues

If you're still having issues, it could be that:

  • You don't meet our network or hardware requirements
  • Your internet is currently unstable
  • In case of latency, you're too far away from each other and we couldn't beat the laws of physics