both of those cpu's will bottleneck a r9 290x. That is a seriously powerful graphics card capable of being slightly bottlenecked by a 8 core amd fx8350. There are even some reports of i5-3570k bottlenecking unless overclocked above 4.5ghz. I don't have any handy links but a simple dual core pentium or aging 1st gen i5 won't work out well. Either plan on upgrading your mobo/cpu in the near future or look into more entry-level gpu's.
I think you will have trouble for sure with the pentium one,even if its oc.I dont have much of exp,but r9 290x could bottleneck even with fx-6300 with oc,so i guess the pentium one is a trouble.