u/Almook

I am the proud owner of a Dell 52" (U5226KW), which runs up to 6144 x 2560 at 120Hz.

My Chromebook (Asus CX54) with an Intel Core Ultra 7 155U and Intel Graphics iGPU runs this natively over thunderbolt no problem at all at full 120Hz.

I recently purchased the 2026 Dell XPS 14 with the latest Intel X7 358H Panther Lake chip with the Arc B390 GPU running Windows 11, it will run the full resolution, but only at 60Hz, if I kick it to 120Hz it down steps the resolution to 3840 x 2160 (4k) - and looks pretty terrible too, blurry etc.

This seems strange to me that a 3 year old chipset is fine, the latest one struggles.

Intel spec sheets don't reveal much:

https://www.intel.com/content/www/us/en/products/sku/237327/intel-core-ultra-7-processor-155u-12m-cache-up-to-4-80-ghz/specifications.html

https://www.intel.com/content/www/us/en/products/sku/245527/intel-core-ultra-x7-processor-358h-18m-cache-up-to-4-80-ghz/specifications.html

Could it simply be a Windows 11 driver issue?