tbh i wasn't getting at future proof as cutting edge of technology...
but ok i think i'm gonna give up trying explain
You explained your point here
if i buy a 4870 1gb thinking it'll future proof me for let say 8months then if a few games comes out lets say in a month and if they run crap on it, how is that future proofing. we have no idea whats coming is in software/games specs, for the hardware.
that is my point.
Which is 2 aspects not one & you have to look at the 2 separately & not as one because the game can run crap for 2 reasons.
Lack of grunt or lack of Vram.
Your example will be likely grunt in that case as in 8 months 1GB of ram will still be the most common & performance due to grunt, you would buy a more powerful card to begin with if that was a concern, grunt & not mem.
That's why i had 2 x 1900xt CF that lasted me 2 years as i knew the limiting factor then for the life of the cards would not be the mem.
A friend of mine who plays more games than i do who runs the latest games is still running a 1800xt 512MB which was overkill for the time that i sold him all those years ago on a 1440x900 monitor. if it was a 256MB version then its more than likely would have been replaced before now.
Its seems that you look at future proofing as people trying to obtain a fail safe scenario that will guarantee things in future events which is impossible as we don't know the future & because of that they should not bother giving themselves every possible chance of it by buying as wisely as they can now to help the chances of things working out better in the future.
I see many here doing just that who have not bought wisely in the past & having to make upgrades because of it & for no other reason with people thinking of upgrading from a 4870 512MB to a 4870 1GB.
Future Proofing is about giving yourself the best possible chance without having to do an unwanted upgrade in the future on a given component with a budget & resource at hand at the time of buying.
If you are forced to make change for things out side of your control then at least you did all that you can with none of the you could have done more before hand hanging over your head.
Stepping away from the gfx card example to what to the OP is asking for with the setup.
AM3 CPU with mobo AM3 DDR3 Ram is the wiser choice with buying from scratch as of what is available now & not on a some hypothetical future of another socket & DDR4 coming within the next year which no roadmap gives any hint of. There would have to a be worth while cost difference not to go AM3 CPU with mobo AM3 DDR3 Ram at this time & if there was to be AM3+ cpu it would likely be backward compatible to AM3 like AMD history has repeated in the past with lower HT on the AM3 mobo.