Hi. I'm the UI3 developer and also the person who wrote the hardware recommendation
wiki and recommended multiplying megapixels per second times 10 to determine a minimum cpubenchmark.net score. Sub streams drastically reduce the megapixels per second your system needs to process at any given time, which is why relatively weak systems are still so good for
Blue Iris these days.
Anyway, multi-cam streaming to UI3
can be very CPU intensive but there are a lot of things you can tweak to reduce the CPU cost.
- Sub streams are once again the biggest help, as it drastically reduces the number of source pixels that Blue Iris must rescale to create a group video frame.
- Use a conservative frame rate limit for the group stream (e.g. 10 FPS). This setting is found near the top of blue iris's local console. There's a dropdown box with each of your camera groups in it, and a gear icon just to the right of it which opens some group settings including the max frame rate for streaming.
- Use a conservative resolution for the group stream. This is controlled by two things in UI3: 1) The regular streaming quality choice, and 2) you can right click a group stream in UI3 and choose Group Settings and from there you can use a slider to control an additional limit for the max resolution of group streams. Generally I recommend keeping this around 3000 or less. It is only 1440 by default which is quite conservative, but would actually be fairly decent if you're only showing 4x D1 resolution sub streams on one screen.
- As a last resort, you can use hardware accelerated encoding if you have an Nvidia GPU with NVENC. The setting for this is in Blue Iris Settings > Web server > Advanced, where you must configure NVENC individually for each streaming profile (only Streaming 0 is used by UI3 by default). Note that consumer-oriented cards have an encoding session limit but that can apparently be overridden by some kind of software or driver hack, I'm not sure of the details. I have no idea how much NVENC may or may not improve CPU usage.
