PC Integratd graphics ???

Looking to purchase new computer.
Looking at all the weekend ads, almost all of the deals offered
include integrated graphics.

My question??

Are the integrated grapics being ofered on these new machine
sufficient to run flight sim programs, or do you really need a
seperate card. Also trying to keep within budget, if buying a card I
see reference to direct x. If i buy a card, do i need to concern
myself with the latest issue of direct x.

TIA

Ludlow, Tomball TX