I have recently been trying to use an LG 40UB8000 as a monitor for my dell precision 5520 (Intel 630 + Quadro M1200), and I seem to be limited to 30Hz at 3840X2160.
I am using a Thunderbolt 3 > HDMI adapter and HDMI 2.X cable, both of which are advertised and confirmed by customer reviews to support 4K@60Hz.
When using the pre-installed "dell approved" graphics drivers, I am only able to select 30Hz, and the "custom resolution" section is not available by default in the Intel Graphics Control Center (dell doesn't update this automatically so you have to do it manually).
After manually installing the latest Intel graphics driver via device manager, I now have the option to set a custom resolution, but when I put in the 4K@60Hz options and hit "add", there is a dialog box which reads "the custom resolution exceeds the maximum bandwidth capacity".
I know that the TB3 port on my computer is capable of this 4K60, as I am able to output 4K60 on an actual monitor via the DisplayPort (it does this automatically without any custom resolution nonsense), so I have no idea where the bandwidth bottleneck is.
I may try returning the TB3 adapter to Amazon and try another one, so if anybody has a suggestion for one that is confirmed to work this would be greatly appreciated.
HDMI is the bottleneck
Processor Graphics ‡ Intel® HD Graphics 630
4K Support Yes, at 60Hz
4K support indicates the product's support of 4K resolution, defined here as minimum 3840 x 2160.
Max Resolution (HDMI 1.4)‡ 4096x2304@30Hz
Max Resolution (DP)‡ 4096x2304@60Hz
Max Resolution (eDP - Integrated Flat Panel)‡ 4096x2304@60Hz
https://ark.intel.com/products/97459/Intel-Core-i5-7440HQ-Processor-6M-Cache-up-to-3_80-GHz Intel® Core™ i5-7440HQ Processor (6M Cache, up to 3.80 GHz) Product Specifications
https://ark.intel.com/products/97496/Intel-Core-i7-7820HQ-Processor-8M-Cache-up-to-3_90-GHz Intel® Core™ i7-7820HQ Processor (8M Cache, up to 3.90 GHz) Product Specifications
Thanks for the reply.
I know that the precision's HDMI Port is unable to do 60Hz (HDMI1.4).
I am using the USB C/TB3 port on the precision, which I know can output 4K @60hz as I have done so on a monitor. The adapter, cable, and tv are all cabable of 4k60 as well accordin specs and customer reviews.
it seems like the dell computer somehow doesn't like the Thunderbolt adapter, and is preventing my desired output despite all the hardware being capable of handling 4k60.