TDU1 and TDU2 are playable on Core i5 4210U with integrated Intel HD 4400
I tried to run TDU1 (Test Drive Unlimited 1) on the computer with CPU Core i5 4210U which has integrated graphics nvidia 4400
And game run smoothly, default/medium video settings in the game, approx 1280x720px(was default). Can recommend, all nice.
TDU2 in comparison was also playable, but the driving was not that pleasant, especially above 250kmh as the scenery was like fuzzy, not sharp maybe as a result of low frames per second (FPS). Eyes would be quickly tired. But no frozing. But if one is ambitious/aspiring gamer, i would pick 6000+ Intel HD instead of HD 4400 or pick stand alone graphics like GTX840M +
TDU 1 CPU/GPU graphs:
TDU 2 graphs was like 90% load both gpu and cpu and experience was not perfect. Where TDU1 were like 70% load and experience was good.