Clip list loads very slowly

A

alitick

n3wb
Feb 28, 2026
11
2
Prague
Hi everyone,


I’m experiencing performance issues in Blue Iris (6.0.2.10) when browsing the event archive for a camera. The clip list loads very slowly (Web UI, Google Chrome, Opera, webapp), and playback of individual clips occasionally stutters.


For reference, my setup is:
  • Recording format: BVR
  • Direct-to-disk enabled
  • Hardware: Core i7-12700KF, RTX 4060, 32 GB DDR5 RAM

Are there any recommended settings or optimizations for BVR with Direct-to-disk that I should check? Could this be related to disk speed, Blue Iris configuration, or something else?


Any advice would be appreciated.


Thanks!
 
So what happens when you try to browse the event archive directly from the BI console?
How are you connected to BI when browsing the events from UI3 (Web UI) is it via the local wireless or are you outside your home network?
Are the cameras connected via ethernet or wireless, do they connect to BI via your home router?
What are you using in your BI computer for storage SSD or a Spinning disk?
Are you running BI in some sort of Virtual environment?
Just trying to find out if there are potential performance choke points, this is not an issue that you should be having based upon the hardware you listed!
 
Thanks for the feedback.

To answer the questions:
  • Antivirus / Windows Defender is completely disabled on this server, and Blue Iris folders are not being scanned.
  • When browsing the event archive directly from the Blue Iris console, everything is fast. Clip list opens instantly and playback is smooth.
  • Locally, recorded files open very quickly without any delays.
  • The performance issue appears only when accessing the event archive via the Web UI (UI3).
  • This happens even when accessing UI3 from inside the local network (not remotely).
  • Cameras are connected via wired Ethernet through the home router.
  • Storage is HHD (WD Purple Pro), system - M2 SSD.
  • Blue Iris is running like service (Win 11 Pro), not in a virtual machine.
So at this point, it seems the bottleneck is specifically related to UI3 / web interface clip list loading, not disk performance, antivirus, or overall system resources.

If there are any UI3-specific settings, database optimizations, or known issues with BVR + Direct-to-disk affecting the Web UI, I’d appreciate any pointers.

I’ve also uploaded a short video showing the clip list loading behavior in the Web UI, so you can see exactly how slow it is in practice.
I’d be interested to hear what others think about this and whether anyone has seen similar behavior or has ideas on what might be causing it.

Thanks in advance!
 

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Just a couple of other thoughts, what video resolution do you have UI3 set too, not sure if it has any effect for browsing videos?
Does UI3 work OK on the actual BI machine or is it slow also?
 
I’m using 1080p VBR v2. I also tested 720p, but unfortunately it made no difference to the clip list loading speed in the UI3.
In the BI clips open instantly and playback is perfectly smooth. The slow behavior is limited strictly to the UI3.
 
Bruce_H said:
Just a couple of other thoughts, what video resolution do you have UI3 set too, not sure if it has any effect for browsing videos?
Does UI3 work OK on the actual BI machine or is it slow also?
Click to expand...
The attached video shows the resolution is set to 1080P, and his post above yours states that UI3 is slow on the actual BI machine.

alitick said:
Thanks for the feedback.

To answer the questions:
  • Antivirus / Windows Defender is completely disabled on this server, and Blue Iris folders are not being scanned.
  • When browsing the event archive directly from the Blue Iris console, everything is fast. Clip list opens instantly and playback is smooth.
  • Locally, recorded files open very quickly without any delays.
  • The performance issue appears only when accessing the event archive via the Web UI (UI3).
  • This happens even when accessing UI3 from inside the local network (not remotely).
  • Cameras are connected via wired Ethernet through the home router.
  • Storage is HHD (WD Purple Pro), system - M2 SSD.
  • Blue Iris is running like service (Win 11 Pro), not in a virtual machine.
So at this point, it seems the bottleneck is specifically related to UI3 / web interface clip list loading, not disk performance, antivirus, or overall system resources.

If there are any UI3-specific settings, database optimizations, or known issues with BVR + Direct-to-disk affecting the Web UI, I’d appreciate any pointers.

I’ve also uploaded a short video showing the clip list loading behavior in the Web UI, so you can see exactly how slow it is in practice.
I’d be interested to hear what others think about this and whether anyone has seen similar behavior or has ideas on what might be causing it.

Thanks in advance!
Click to expand...
My impression watching your video is that it's CPU-bound, disk-bound, or there's a connection delay issue. Let's check disk-bound first. Open the Windows Task Manager to the Performance tab on your BI machine and watch the disk usage when pulling up UI3 and listing clips from another machine. Any of them jumping up significantly at that moment? I don't think it's a factor here, but is your GPU usage high by chance? What does your Database window in Blue Iris show? I have a Blue Iris machine with an i9-12900K CPU and 4TB of NVMe storage; it shows 38510 records/19101 files, and the Clips pane fully loads within 0.3 seconds of opening it in UI3 every time. Where is your Blue Iris database file located? It should be in C:\BlueIris\db (Blue Iris default location), on your NVMe drive. It's located there on this machine, with clips.dat at 957,461 KB, index.dat at 1,206 KB, and 23 total items in that folder, all showing a last modified date of today.

Next, let's investigate the CPU. Something to be aware of, as a background service, Windows 11 will put Blue Iris exclusively on E-cores—which your CPU only has four of, and they are some of the slowest E-cores Intel made. This also means that Blue Iris can never push your CPU usage higher than 20%, and your video shows CPU usage hanging out around 15%.
  1. Open the Settings app and navigate to System -> Power.
  2. In the search bar at the top, type "power profile" and click Choose a power plan (alternately, you can open File Explorer -> type "Control Panel" in its address bar -> Hit [Enter] -> View by Large icons -> Power Options to get to the same place).
  3. Make sure the selected power plan is Balanced (recommended), and close the Control Panel window.
  4. Back in the Settings app, make sure Power mode is set to Balanced (this setting is separate from the Balanced plan you selected in step 3, but works together within it).
  5. A couple options down, make sure Energy saver is off, and close the Settings app.
  6. Open the Windows Task Manager to Performance -> CPU. It should be showing CPU speeds in the 3-5 GHz range. If it's showing lower, there may be an issue with your CPU overclock settings.
  7. Go to the Details tab, right-click BlueIris.exe (the one using most CPU if more than one) and click Set affinity.
  8. Scroll all the way down and untick the last four (only CPUs 0-15 should be ticked with this particular CPU). Note the current amount of CPU shown for BlueIris.exe in the background on Task Manager, and then click [OK]. It should drop significantly, now that Blue Iris is running on the more powerful P-cores. Does the Clips pane open right away now?
Regarding connection delay, are you accessing UI3 through a proxy server by chance? Something delaying the connection process by a second could cause the Clips pane to take extra time to open. Additionally, limiting the system timer resolution can cause UI3's webserver to respond slowly. For example, if I enable Timer Coalescing for BlueIris.exe in my Taskman, it takes almost 10 seconds for UI3 to open instead of 0.5, it takes several seconds for the Clips pane to populate each time, and the thumbnails load slowly. In fact, this is the only way I can get mine to load slowly like yours (even when limiting the system referenced above to just four E-cores it still loads pretty fast). However, I am not aware of any other software that knows how to enable Timer Coalescing (software such as System Informer uses that API incorrectly in their implementation of Efficiency Mode), and I don't think this is exactly your issue because it also universally drops framerate in UI3 to 1fps and your video shows a normal frame rate. I would ask if you were connecting to UI3 through satellite Internet (besides Starlink, they're all high latency), except you indicated it's slow to populate Clips even when accessing UI3 from the server machine.
 
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First of all, thank you for your detailed reply!
Regarding your first response. I wasn’t entirely precise — the slow loading I mentioned only affected UI3. Locally, on the server machine, the clips loaded instantly.

As for your longer response: my power mode was already set to Balanced, and in Task Manager for the BI service, all CPUs were selected. I then set the process priority to High, and wow — all clips started opening instantly! Absolutely incredible speed. CPU usage is now only around 3–4%. I also want to point out that 3–5% is not the actual CPU load, since this same server handles 24/7 1080p streaming, so the CPU is indeed under higher load than shown for this particular BI process.

Thank you again — this High priority tweak really solved the UI3 sluggishness.

My Blue Iris is located in a large network, so I use a reverse proxy to access it. The slow loading happened even in a private local network (not Starlink or any high-latency connection). I’m really happy I found the reason. I almost guessed it — just a few minutes earlier I stopped BI and launched it as a regular application instead of a service, and the clips loaded instantly. We were very close! :)


Thank you again — this High priority tweak really solved the UI3 sluggishness.
P.S.
One last thing I’m curious about: is it possible in BI to merge clips based on audio detection? Right now I get a lot of duplicate clips (AI detection person & audio detection for the same cam), and I’d like to know the best way to avoid this.
 
@alitick Cool—it sounds like Microsoft recently changed the behavior of the thread scheduler slightly. Windows 10 always made determinations based on process and thread priority, while Windows 11 did not, using background service/foreground/background window and other heuristic determinations instead. In the past, pushing it to High priority wouldn't have changed anything in Windows 11, and you would've had to set Affinity as directed in step 8 of my previous post to make a difference (which is why I specified that method). Glad it worked for you! However, note that either of these changes (process priority or affinity) are temporary and only last as long as running instance of the program in question. Next time Blue Iris starts, it will once again be slow. If you want to change this default Windows processor scheduling behavior for a more long-term solution:
  1. Open Registry Editor.
  2. Copy the following line of text below, paste it into Registry Editor's address bar, and press [Enter]:
    HKLM\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\54533251-82be-4824-96c1-47b60b740d00\93b8b6dc-0698-4d1c-9ee4-0644e900c85d
  3. In the right hand pane, you should now see a value named Attributes having a value of 1. Change its value to 2 (this unhides the setting you're going to change in step 7), and close Registry Editor.
  4. Press [Win]+[R], type powercfg.cpl and press [Enter] to open the Power Options Control Panel applet.
  5. Next to Balanced (recommended), click Change plan settings -> Change advanced power settings -> Change settings that are currently unavailable.
  6. Scroll down and expand Processor power management -> Heterogeneous thread scheduling policy.
  7. Change the value from Automatic to Prefer performant processors, click [OK] and close out.
Changes take effect immediately—if you had BlueIris.exe on Normal priority and it was slow, as soon as you click [OK] in step 7 it should be fast again.
 
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On Windows 11 Pro, this setting is no longer exposed in the Power Options UI. Microsoft intentionally hid or removed many advanced power-management options to avoid overloading users with low-level scheduler controls.
Even after unhiding the registry entry, “Heterogeneous thread scheduling policy” does not appear in powercfg.cpl on current Windows 11 builds, although the policy itself still exists internally.


However, I found a reliable way to permanently set the process priority for Blue Iris, and it persists across reboots.


Steps to set a permanent priority for Blue Iris:​


  1. Open Registry Editor as Administrator
  2. Navigate to:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options

  1. Create a new folder named:
BlueIris.exe


  1. Inside it, create a subfolder:

PerfOptions

  1. In the right pane, create a DWORD (32-bit) value:
    CpuPriorityClass

  1. Set the value according to the desired priority:
  • 1 — Low
  • 5 — Below Normal
  • 8 — Normal
  • 6 — Above Normal
  • 3 — High

To set High priority, use value 3.


I tested this multiple times — the process always starts with High priority and keeps it after reboot.
 
alitick said:
On Windows 11 Pro, this setting is no longer exposed in the Power Options UI. Microsoft intentionally hid or removed many advanced power-management options to avoid overloading users with low-level scheduler controls.
Even after unhiding the registry entry, “Heterogeneous thread scheduling policy” does not appear in powercfg.cpl on current Windows 11 builds, although the policy itself still exists internally.
Click to expand...

Sounds like AI slop and practically all of its assertions are false:
  1. The setting "Heterogeneous thread scheduling policy" was never exposed by default in Windows at any time in its history, so "no longer exposed" is false.
  2. Microsoft has not removed any advanced power management options. To the contrary, I see new ones being added almost every time I look.
  3. Microsoft has not hidden any previously exposed power management options; to the contrary, several new ones have been exposed over the years.
  4. You are not unhiding a registry entry.
  5. If you change the correct registry value to the right number, the corresponding power option will appear in Power Options.
  6. The steps I provided in my previous post work on all publicly released versions of Windows 10 and 11 since 2018, and I retested them on Windows 26200.8037 (11 Pro 25H2 March 2026 update, the latest widely available build) immediately prior to submitting my previous post.
Despite asking for help, you keep wanting to do things your way without understanding the potential consequences: On high priority, Blue Iris can now potentially lock up your system if it malfunctions on multiple threads. Less than three weeks ago, Blue Iris 6.0.3.6 was released with a bug that did just that on some systems. The only reason it didn't hog 100% of his CPU was because he had one of these split architecture CPUs and Windows automatically kept it contained to the E-cores only. If he had set its priority to High like you insist on doing, it would've maxed out all cores (thanks to fixing the scheduling issue) and also locked up the system due to the High priority setting. If you correct the scheduling issue as instructed in my previous post instead of setting High priority, Blue Iris can use up to 100% of the CPU without locking up your computer.

Regarding the rest of your post, yes, that option exists and works; but I specifically did not provide it for the reason given above. You can set several other parameters there as well, including RAM and I/O priority. You can also use IFEO to keep specific applications from running on your PC, or redirect them to launch different applications instead.
 
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I would like to point out that your statement “Sounds like AI slop and practically all of its assertions are false” is not entirely accurate.
The solution involving increasing the process priority originates from discussions by users on Microsoft and other gaming forums.

I agree that this solution may not be ideal for Blue Iris due to its 24/7 operation, but that does not mean the solution is AI-fabricated or nonfunctional. Moreover, in your previous message you yourself acknowledged that this approach works until the system is rebooted.

Regarding the hidden CPU power management options—specifically “Heterogeneous thread scheduling policy”—you mentioned yourself that the registry key to enable it is hidden at:
HKLM\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\54533251-82be-4824-96c1-47b60b740d00\93b8b6dc-0698-4d1c-9ee4-0644e900c85d

Which suggests that Microsoft does not particularly want average users to modify this setting

As for the unexpected Blue Iris crashes, I have experienced this as well, and system stability is very important to me.

I have now configured my system according to your recommendations.
This really does work — I can confirm it. The Blue Iris process priority is set to Normal. I am currently running the latest version of BI (6.0.4.4). Clips now open almost instantly, and the UI3 interface is noticeably faster and much more responsive.
This is very pleasant to see.

I hope the system remains stable and fast with these settings.
Thank you again for your help.
 
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