All Intel Integrated GPU suck (don't know about Intel HD 4000 though) , it will bottle your CPU if you run anything higher than 480p
AMD 6670 is enough for 1080p so 6870 should do fine at 2000p
Check this thread
Internal Resolution (IR) : 1x = 480p
IR : 2x = 720p
IR : 3x = 1080p
IR : 4x = 2000p
Although your CPU is Sandy Bridge but 2.4Ghz won't cut it . Sooooo :
Overclocker : Get i5 2500k @ 4.4Ghz + AMD 7750 (AMD 7000 series is faster , less heat -> overclock higher , only 109$ for 7750)
Non-overclocker : Get i3 2120 + AMD 7750
AMD 6670 is enough for 1080p so 6870 should do fine at 2000p
Check this thread
Internal Resolution (IR) : 1x = 480p
IR : 2x = 720p
IR : 3x = 1080p
IR : 4x = 2000p
Although your CPU is Sandy Bridge but 2.4Ghz won't cut it . Sooooo :
Overclocker : Get i5 2500k @ 4.4Ghz + AMD 7750 (AMD 7000 series is faster , less heat -> overclock higher , only 109$ for 7750)
Non-overclocker : Get i3 2120 + AMD 7750
Laptop: (Show Spoiler)
Mini PC :: (Show Spoiler)