Recent my brought computer having below spec;
(1) CPU G3220
(2) RAM 4GB
(3) MB Asus H81M-plus (manufacturer said HDMI support 1.4a and max.resolution is 4k)
(4) MONITOR 27" WQHD 2560x1440 display
(5) PC and Monitor connected thru HDMI 1.4a cable
(6) OS Windows 8.1k 64bit
IGP driver updated with;
Intel® Iris™ and HD graphics Driver for Windows 7/8/8.1* 64
File name: Win64_15338.exe
AND, intel(R) HD Graphics property show Driver version is 10.80.10.3345.
It's work fine BUT display resolution limited 1920x1080.
I wonder, is G3220 & H81 + 1.4aHDMI wouldn't run up to 2560x1600 display??
The link below shows the information about your graphics controller technology.
The processor model G3220 comes with 3rd generation graphics technology and it does support 2560*1600 screen resolution, although, your computer manufacturer may limit screen resolutions depending on their computer design.