10 sec+ Latency w/ Full Raspbian OS

Thanks for reporting this! Sorry about the latency you're hitting.

OS as the cause

A 10 second delay would be a 50x increase over the normal latency, so it's unlikely just a difference in OS.

Raspberry Pi OS Lite is the only officially supported OS, but it should work fine with the full version. You can run the top command to check whether your CPU is at 100% or if you're out of memory.

Throttling as the cause

Throttling is an interesting idea. It shouldn't be happening unless your device is in an unusual environment or you're otherwise running heavy loads.

Can you try these commands?

sudo vcgencmd measure_temp
sudo vcgencmd get_throttled

If your Pi has throttled the CPU since boot, you'll see a non-zero code for get_throttled that corresponds to these values.

Network link as the cause

My guess is that the bottleneck is the network link. How are you connecting to the TinyPilot? Is it on the same local LAN or is the connection going over the Internet?

The video stream is in MJPEG, which is very bandwidth-hungry. I'm planning to migrate away from MJPEG to a more efficient encoding in the next few months, but there's a workaround in the meantime.

You can reduce the network load by dialing down the streaming settings. To do this, SSH into the TinyPilot and run:

sudo nano /lib/systemd/system/ustreamer.service

Replace the ExecStart section with this:

ExecStart=/opt/ustreamer/ustreamer \
 --host 127.0.0.1 \
 --port 8001 \
 --encoder omx \
 --format uyvy \
 --workers 3 \
 --drop-same-frames 30 \
 --persistent \
 --dv-timings \
 --quality 50 \
 --desired-fps 10 \
 --resolution 640x480

Save the changes and then run this command to restart the stream with the new settings:

sudo systemctl daemon-reload && sudo service ustreamer restart

Caveat: The video streaming settings will be overwritten if you run the TinyPilot update script. To make the settings persist through updates, you can follow the Advanced installation instructions.

Tested new power supply and it is putting out correct voltage and amps consistently.

However, the problem is BACK!

The interesting part is that if I refresh the webpage it instantly displays real time output from the host computer. This is about 7 seconds faster than not refreshing the page.

Is there something getting hung up in the code that I am missing here? I'd be willing to do a shared terminal session with you if you want to take a peek. I could give you access to my VPN as well if you want to see the issue first hand? I am completely at a loss here...

I think I may have narrowed it down to an issue with the pi overheating itself. When the pi gets to about 45 degrees it starts slowing down significantly. Strangely though the command you gave me to check for throttling consistently returns 0x0.

I am installing a much better heat sync and fan tomorrow to address the heating issue. I have been able to keep it at 39 degrees with my current setup but when we were testing it was out of the case and therefore heat became a serious issue. Without fan we were running at right around 56.

If the issue persists further I will leave an update here. Still willing to let you take a look if your interested.

I think the heat is a red herring. 45 C isn't very hot for a CPU. I don't think the Pi typically begins throttling until the 65-70 C range.

What is the connection between the browser and the TinyPilot? You mention VPN, so I assume it's over the Internet. Does it go through any web proxies? MJPEG is an uncommon protocol, so web proxies often handle it poorly. Some browsers also get slower if you leave the page open for long periods because they leak memory when trying to render MJPEG.