u/Glum-Rabbit3108

Hi,

I’m having a strange issue with my Lenovo Legion Slim 5 (16APH8):

Specs:

• Ryzen 7 7840HS
• RTX 4070 Laptop GPU
• 16 GB RAM
• Windows 11

Problem:

• System freezes completely for ~10 seconds
• Screen goes black
• Either:
  • PC restarts, OR
  • returns to desktop with very low brightness
• Happens even during light use (browser)

Key observation:

• When AMD Radeon 780M (iGPU) is enabled → problems occur
• When I disable the AMD iGPU → system becomes fully stable

Also noticed earlier:

• “Hardware reserved memory” jumped to ~8 GB
• After disabling iGPU → RAM behaves normally again

What I’ve tried:

• Clean reinstall of NVIDIA drivers
• Installed AMD Adrenalin (got Error 207)
• BIOS checked (UMA frame buffer set to 512MB)
• Windows fully updated
• Lenovo Vantage → no updates available
• Discrete GPU mode enabled

Current workaround:

• AMD iGPU disabled → system works perfectly

Questions:

• Is this a known issue with Radeon 780M + Lenovo Legion?
• Any stable driver version I should try?
• Should I use Lenovo-provided drivers instead of AMD Adrenalin?
• Could this be BIOS-related?

Any help or similar experiences appreciated 👍