While Doom 4 will be powered by the same id Tech 5 technology as Rage, co-founder and designer John Carmack says it would appear to be "a totally new game engine".
Whereas the open-world shooter Rage will run at 60FPS, id will be able to chuck "three times as much horsepower" at Doom 4 running at 30FPS.
The announcement earlier this year of another Doom shocked many given the agonising wait for fans to receive the third instalment. There's been no platform or date specifics for Doom 4 but Rage will be touching on PC, Xbox360, PS3 and MAC.
"It's going to look like a totally new game engine on there, even though it's going to be built on the four years of effort that we spent developing this generation of technology," Carmack said in an interview with .
It's likely more juicy morsels will make their way to the masses at QuakeCon, which runs at the end of this month.