Troubleshooting Lag, Latency and Quality Issues

For lag, latency or quality issues, here's how to look into network and hardware related causes, and potential solutions.

 

Checking latencies

With a very visually active game or video on the host, press Ctrl+Shift+M on the guest to see the information below.

overlay_demonstration.png

Decode (guest) and Encode (host) is the time the device takes to handle a single frame. High numbers can mean major issues to the stream. When streaming 60fps, you don't want to go above 16ms. At 30fps the threshold is 33ms.

What to do if the decode or encode latencies are too high?
  • Lower the resolution and FPS of the host until it's at a safe amount. Resolution is usually changed through Windows but sometimes also in-game
  • You may have a different experience from tweaking between fullscreen and windowed (or windowed borderless)
  • If the host happens to have experimented around with advanced settings in Settings > Host > Edit the configuration file, remove them and restart Parsec. They can easily worsen the experience if not carefully configured
  • If the guest's overlay says Software H.264, Parsec isn't using the hardware decoder which results in much worse decoder latency. There's a setting in the overlay itself and Parsec's settings to change the decoder to something else, but if the guest's hardware is too old, they might be unable to use a hardware decoder at all
  • If the host has an AMD card, AMD is usually known for having worse encode than NVIDIA and even Intel. You should be fine at low resolutions. If all guests support h265 and have it turned on, you may see better performance
  • If the host has a G-Sync monitor, try to disable G-Sync and check if the encode latency improves
  • Hosts on NVIDIA may get better encode by setting Parsec to maximum performance in the NVIDIA Control Panel
  • (For paid users) Having 4:4:4 color accuracy on increases the load (especially with h265). Try it without h265 or completely off

Network is the ping between the guest and host. The more latency you have, the more time it takes for you to press a button and see it on the host. Below 30ms is good, and below 60ms is still fine for most people.

What to do if the network latency is too high?
  • Both sides should 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 Wi-Fi and you can at least test an ethernet cable for a moment, try it out and see if your situation improves
  • VPNs can introduce additional latency and should be avoided if possible
  • You may be physically too far away from each other. Parsec unfortunately isn't able to break the laws of physics yet
  • If you're not physically too far away, the route being taken by your connections may be currently poor. This is unfortunately basically out of your control. Or, either side's connection may be poor in other ways that are covered in the network reliability part of this article, below. Note that Parsec is peer-to-peer, so your connection isn't going through Parsec's servers, it's entirely up to the guest and host's connection

 

Checking network reliability

Don't disregard this if you think your internet is fine. To check, host a session via desktop sharing (not Arcade). Put a very visually active game or video on the host for a few minutes, then access the console on the host and look at the N:0/0/0 numbers.

console_log_example.png

Ideally this should be very close to 0/0/0. If the numbers are incrementing by hundreds in minutes, the connection between the guest and host is getting affected by packet loss. Parsec will lower the quality for any increase to compensate, but you'll also lag if it increases a lot.

What to do if the N: numbers are too high?
  • These numbers can generate false positives if the decode or encode latency is over the recommended threshold, make sure you checked that's not the case in the previous section about latencies
  • Both sides should 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 Wi-Fi and you can at least test an ethernet cable for a moment, try it out and see if your situation improves
  • Make sure that the bandwidth limit in the host settings isn't too much for either side's internet speeds. Keep it at least 5mbps less than the host's upload and the guest with the worst download speed
  • Beware of other apps or devices on your network that might be making use of your internet, perhaps not leaving enough for Parsec
  • Some routers have defective Intel puma chips that don't handle intensive network tasks very well and often cause severe stream issues. Search on TechInfoDepot for your modem/router. If yours has the defective chip, you should look into replacing it
  • If anyone has internet speeds slower than the recommended, it causes this. The host needs at least 10mbps upload and 2mbps download per guest. The client needs at least 2mbps upload and 10mbps download
  • If the host happens to have experimented around with advanced settings in Settings > Host > Edit the configuration file, remove them and restart Parsec. They can easily worsen the experience if not carefully configured
  • The connection on either side might just be poor, or the connection route being taken is currently poor. Note that Parsec is peer-to-peer, so your connection isn't going through Parsec's servers, it's entirely up to the guest and host's connection
  • If you're connecting PCs on the same house with ethernet cables, it should be flawless. If it isn't, something is faulty, be it the cables, the router, switches you have, or the PC. Experiment with different PCs in the house, remove switches, try out the same ethernet cable on different PCs to check if the cables may be faulty. Ideally, while testing, keep it as 'PC <-> cable <-> router <-> cable <-> PC'

 

Other things to consider

What else to look into if the console log and latencies seem fine?
  • If everyone is looking at the action from Parsec (the host isn't looking at the original screen or you're on a cloud PC), it's possible the game itself is lagging. If no one can check the actual screen, use tools to monitor the FPS and general performance of the game
  • If the stream is stuttering somewhat, try turning on V-sync in Parsec's client settings and restart Parsec. People usually associate V-sync with preventing screen tearing, but on Parsec it can noticeably improve the delivery of frames in other big ways. If you don't notice an improvement, keep it off for saving some latency
  • If the host and guest have differing refresh rates, it might result in what looks like stutter. Consider tweaking the refresh rate if you suspect that's the case
  • Guests can try out a different renderer in Settings > Client > Renderer. Most Windows guests will have a better time with DirectX, and Intel HD Graphics 4000 and older do not support OpenGL well
  • If you're getting underwhelming quality at high bitrates, and you happen to have H265 on, try turning it off
  • If you feel way more latency than you get by combining the decode + encode + network from the overlay, your guest device could be at fault in ways that even decode won't tell you. Try being a guest in different devices to check this, confirming that your latencies and console log are still good. If you have a Raspberry Pi, make sure it has a proper power supply, isn't throttling and use the "Performance" CPU governor on all cores