8K HEVC (H.265) video decoding uses CPU instead of iGPU - Intel Core Ultra 5 135U W11 Education

[FrancisDu]

Hello,

I’m experiencing a repeatable issue with 8K video playback on multiple new systems that all use the Intel Core Ultra 5 135U processor with integrated graphics.

System details

• Laptop model: Dell Latitude 5450, 8 GB DDR5

• OS: Windows 11 Education, fully updated

• Updates: Windows updates are applied through our organization’s controlled/filtered update system, and all Intel drivers (including graphics) are updated manually via Intel Driver & Support Assistant.

• Anti-virus: Windows Defender only

Problem description

• Any 8K HEVC (H.265) video lags badly in VLC (which is our preferred media player installed on all workstations) and Windows Media Player.

• Video shows gray artifacts while audio remains fine.

• In Google Drive playback in Chrome, the same video streams smoothly (server-side decoding).

• UHD (4K) and lower-resolution videos play perfectly.

Observations

• Task Manager shows CPU spikes to 100% while the integrated GPU video decode engine stays at 0% when playing 8K content.

• For UHD/4K content, GPU video decode is used correctly and CPU usage stays low.

• Same behavior confirmed on several identical Dell Latitude 5450 systems, so it’s not a single hardware fault.

Troubleshooting performed

• Tested different media players (VLC, Windows Media Player).

• Updated BIOS, Intel drivers, and confirmed Windows updates through our managed update process.

• Verified the files are HEVC (H.265) and the CPU is advertised to support this codec.

• Issue reproduces across all identical laptops.

It looks like the integrated GPU is not engaging for hardware decoding at 8K HEVC, forcing software decode on the CPU and causing stuttering.

I’ve attached the requested IDSA zip file.

Please advise if this is a known limitation or bug, or if there’s a workaround/driver update planned.

(Note: this post was drafted with the help of AI to assist with English translation.)

Francis D.

[JezreelZ_Intel]

Hi FrancisDu,

Thank you for reaching out to the Intel Community Forum. To assist us in investigating the issue, please provide the following details:

Have you tried using the OEM driver for testing?

Can you confirm if this issue occurs with all 8K HEVC videos, or are there specific files that exhibit this behavior?

Have you tried using any other media players besides VLC and Windows Media Player to see if the issue persists?

Have you used Display Driver Uninstaller (DDU) to completely remove all residual drivers and installed a new one?

Have you tried adjusting the graphics settings?

Could you provide a screenshot or video of the issue that you are having specially the gray artifacts?

Which gaming platform did you use to download the game?

Additionally, to gain a comprehensive understanding of your system, please use the System Support Utility (SSU). This tool will generate a text file compiling all your system information. You can follow the instructions at this link and send the text file here. Help Guide for the Intel® System Support Utility.

If you have any questions, please let us know. Thank you.

Best regards,

Jezreel Z.

Intel Customer Support Technician

[FrancisDu]

Hi, thanks for the follow-up and for looking into this.

Here are my answers to your questions:

• OEM driver: Yes, I first tried the Dell OEM graphics driver and the issue remains.

• 8K HEVC videos: The problem occurs with all 8K HEVC videos I tested.

• Other media players: Besides VLC and Windows Media Player, I only tested browser playback. 8K plays smoothly in a browser, but we need VLC as our primary media player in our environment.

• Display Driver Uninstaller (DDU): I used DDU to completely remove and reinstall the drivers. no improvement.

• Graphics settings: I adjusted video and graphics settings without success.

• Screenshots: I’ve attached two screenshots showing the gray artifacts.

• Gaming platform: This is not a game download, the issue is strictly with local 8K HEVC video playback.

I’ve also attached the requested SSU data for further analysis.

Thanks again for your help.

Francis Dufresne

[PatrickV_Intel]

Hi FrancisDu,

Thank you for the update. I will look into this further and will update you as soon as a solution is found. I appreciate your patience and understanding.

If you have any questions, please let us know. Thank you.

Best regards,

Patrick V.

Intel Customer Support Technician

[PatrickV_Intel]

Hi FrancisDu, 

Thank you for your patience. I can confirm that the integrated graphics on your GPU does support hardware decoding of 8K @ 30fps for HEVC codec with the following specifications:

• Profiles supported: Main12 420, 422, 444
• Bit depth: 8b/10b/12b
• Level: 6.1

While the hardware can decode 8K@60fps content, it's decode-only (no hardware-accelerated playback). This means if you're watching 60fps 8K content, the system will fall back to software decoding, which may impact performance.

I've personally tested this with the latest drivers using VLC player, and 8K@30fps works perfectly with proper GPU hardware acceleration engaged. You can see the test results in this video: https://www.youtube.com/watch?v=l5JFFP526PY

To verify this works on your system, please try downloading and playing with VLC the following 8K@30 HEVC video file from https://lf-tk-sg.ibytedtos.com/obj/tcs-client-sg/resources/video_demo_hevc.html#main-bt709-sample-4

If you have any questions, please let us know. Thank you.

Best regards,

Patrick V.

Intel Customer Support Technician

[FrancisDu]

Hi Patrick,

Thank you for the clarification and for sharing the test video. I tested the 8K@30fps sample file you provided, and while it does play smoothly on my system, it seems that hardware decoding is still not being used. Task Manager shows that the CPU is taking almost all the load, while the GPU video decode engine remains idle.

I also tried the “HEVC Main Profile – SDR – Sample 1 (8K + 60P)” file from the same site you referenced. This video also plays, but in this case the CPU is driven up to 100% usage during playback, again with no GPU decode activity.

The 8K videos I’m trying to play are recorded on mobile phones (tested with two different phone models). I’m adding this information as a potential lead on why the problem may occur. I don’t know the exact smartphone model the user originally used for their video, but I know that the test video I recorded myself was from a Samsung S23 FE. I’ve attached a screenshot of the codec information for one of these videos for reference.

If it helps with troubleshooting, I can also provide the actual video files so you can test it directly. Please let me know the best way to share it.

Thanks again for your support!

Francis Dufresne

[PatrickV_Intel]

Hi FrancisDu,

Thank you for the update. I will look into this further and will update you as soon as a solution is found. I appreciate your patience and understanding.

If you have any questions, please let us know. Thank you.

Best regards,

Patrick V.

Intel Customer Support Technician

[PatrickV_Intel]

Hi FrancisDu,

Good day!

To help us further investigate the issue, could you please share the file you’re trying to play?

You may upload the file to Google Drive, and kindly provide us with the download link so we can access and review it on our end.

If you have any questions or need assistance with uploading, please let us know. Thank you!

Best regards,

Patrick V.

Intel Customer Support Technician

[FrancisDu]

Hi Patrick,

I’ve uploaded both video files to Google Drive for your review:

• 8KVideo_Original -> the original video file that the user is trying to play.

• 8KVideo_Test -> a test video I recorded myself on a Samsung S23 FE.

In both cases, the videos lag and display gray artifacts during playback.

Here is the Google Drive link to access the files: 8K Video

Please let me know if you encounter any issues accessing the files or if you need additional information.

Thanks again for your assistance!

Francis Dufresne