How to interpret the USB MacBook maximum monitor resolution? I'm wondering if a macbook (USB C only) can support a 49" (5120 x 1440)  monitor display. 

The 2018 Macbook has the Intel® HD Graphics 615 card (per specifications). 


The Intel website for this graphics card has a confusing table for max resolution which cites: 4096x2304@60Hz, 3840x2160@60Hz. 
The card apparently has 16GB of memory. 


Although I am a trained electrical engineer I'm not knowledgeable enough to work out if this card can support a 5120 x 1440 display. 

Is it as simple as ensuring that:

5120 x 1440 &lt; 4096 x 2304?

Or is it more nuanced than that?
Apple selects and manages the graphics drivers, so knowing that another OS might have drivers capable of running the resolution is good information,  but no guarantee you’ll see the same on macOS. 


https://www.apple.com/macbook/specs/


On the plus side, you get super organized support articles explaining all manner of 4K and 5k support across all Mac models, no matter the drivers or internal chipset details. Also on the plus size, the 2018 MacBook is shipping and you can get information that it supports at 60 Hz more megapixels than the display you ask about. 


https://support.apple.com/en-us/HT206587


Our canonical question how to look up detailed specs for all Mac will get you this information:


MacBook [Pro] - how many displays, what resolution/frequency?



  Graphics and Video Support
  Intel HD Graphics 615 Dual display and
  video mirroring: simultaneously supports full native resolution on the
  built-in display and up to 4096-by-2304 resolution at 60Hz on an
  external display, both at millions of colors. USB-C port with support
  for:  
  
  -Charging
  -USB 3.1 Gen 1 (up to 5 Gbps)
  -Native DisplayPort 1.2 video output  


Since your MacBook has no HDMI direct and no thunderbolt, the key missing piece of information is what USB-C video will be supported on that announced but not shipping product.  

If I had to guess, I would speculate that you need DisplayPort 1.4 to make that LG or the similar dell with a 7.3-megapixel total count to run and I’ll also speculate only a MacBook Pro or Air with Thunderbolt 3 will have DP 1.4. You should probably plan for DisplayPort 1.2 or lower for the MacBook “one” models since Apple could exceed their specs, but that is what the MacBook is listed as fully supporting. 

Can LG tell you how that display will function when fed DP 1.2?


https://www.dell.com/en-us/shop/dell-ultrasharp-49-curved-monitor-u4919dw/apd/210-arnw/monitors-monitor-accessories
https://en.wikipedia.org/wiki/5K_resolution