Blue Iris

I am running BI 5.3.3.5 with about ~15 4k cameras using a dedicated Windows machine.

I frequently notice BI will 2x or 3x the baseline CPU utilization, even when no motion is detected. For example, BlueIris.exe will jump from 13% to 25-40% for 5-10 seconds at a time, several times a minute. I plan to add cameras & AI detection in the future but the performance spikes on decent hardware are making me hesitant until I root cause what is keeping BI so busy.

BI dedicated system specs:

• 16GB RAM, 8-core i7-11700 (HT enabled)
• Windows Server 2022 (no extra features enabled)
• SSD storage
• Sub streams are enabled on all cams.
• Direct-to-disk recording. Not using reencoding.
• 1 remote UI3 session
• BI runs in full screen on local desktop

Is there any detailed BI log or real-time activity/thread monitor that can help me understand what BI is doing in the background?

Just a guess, but it may be that those spikes are from other processes or possibly BI moving files around or doing its housekeeping.

Ditto.

A little searching will show that Windows Server can occasionally be problematic running Blue Iris and is usually avoided in favor of Win10, Win10 Pro, or now Win11 -- with reservations by many with Win11 so soon as well.

Perhaps observing your RAM (and other) activity when the CPU spikes occur will reveal something there? A review of your BI storage (and other) scheduling activity may also show unintended activity with that particular time interval.