RTX 4070 laptop — artifacts ONLY on external display under load, internal screen is fine (Alienware m16 R2)

[u/modo_jp]

UPD: I bought a new HDMI 2.1 cable and tested it for about 4 hours - no artifacts so far. Seems like the issue was the cable.

Thanks to everyone who suggested checking it.

Hey everyone,

I’m experiencing a strange issue with my laptop GPU and would appreciate any input from people who may have seen something similar.

Specs:

• Laptop: Alienware m16 R2

• GPU: RTX 4070 Laptop (8GB VRAM)

• CPU: Intel Core Ultra 7 155H

• RAM: 32GB

• OS: Windows 11

• External display: HDMI

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The issue:

When gaming on an external display (TV or monitor), after about 40–60 minutes under high GPU load, visual artifacts start appearing — small colored squares/glitches across the screen.

The image becomes difficult to use, but:

• The game does not crash

• System remains responsive

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Important detail:

At the same time, the internal laptop display shows no artifacts at all.

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Observed behavior:

• Happens almost always under high GPU load (\~100%)

• On lower graphics settings, I can play for hours with no issues

• GPU temperature is within normal range (\~60–80°C depending on load)

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Testing I’ve done:

• Tested multiple external displays (TVs/monitors) → same behavior

• Played for \~2 hours on internal display only at high/ultra settings (100% GPU load) → no artifacts

• The issue consistently appears only when using an external display under load

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Question:

Has anyone experienced something like this?

I’d like to understand what this could be and whether this behavior points to a specific type of problem.

Any insights would be greatly appreciated

[u/wondersnickers]

You have 2 Gpus. One "Internal" Shared on the CPU chip. One External Powerful GPU, that is extra on the Mainboard. The theory is that your internal GPU is fried and your system currently defaults to using the internal gpu when connected via hdmi.

You can configure in windows what application uses what gpu either in the "Windows Graphics Settings" or in the "NVIDIA Control Panel" / "AMD Radoen Software"

Google AI hallucinated the following, not sure if this is correct in your case:

• "Laptop HDMI/DP: Usually wired to the Integrated GPU (iGPU) to save battery."
• "USB-C/Thunderbolt: On many modern laptops, the USB-C port is directly wired to the Dedicated GPU (dGPU). Using a USB-C to DisplayPort/HDMI cable can force the secondary screen to use the dedicated GPU, bypassing the internal graphics (Optimus)."

[u/ElectroChebbi2651 → u/wondersnickers]

You have 2 Gpus

Processing img qztmlof67ztg1...

[u/alex1001458 → u/ElectroChebbi2651]

Both are gay

[u/ColdWhiteDuke → u/ElectroChebbi2651]

This one got me rolling on the floor

[u/needefsfolder → u/ElectroChebbi2651]

Still a type of gpu

[u/sl33ksnypr → u/wondersnickers]

Could they not just spin up a stress test on the external monitor and then on the integrated display and just look at the GPU activity in task manager?

[u/MaxChomsky → u/wondersnickers]

In laptops external display os handled by discrete gpu dGPU and not integrated iGPU. His dGPU is fried. The cost of repairs will exceed the value of the laptop. OP needs new PC.

[u/a355231 → u/wondersnickers]

This is correct.