You can't do too much with DX11 on a 6790 IMO, I have 2x GTX 460 and I don't use DX11 half the time because my cards just aren't up to it. That is, unless you're playing on a low resolution, what res are you at?
550ti is less powerful than the two cads you mentioned
despite the advice and the Theoretical information I provided
do not buy a graphics cad that is 3 generations old, that's foolish
As for no direct x11 being usable @ w/6790 your resolution that is also not true
Yes you will have to turn some stuff down but really no more than you
would with the 275 the difference is there but they will offer a similar gaming experience only one can offer direct x11
not every game is crysis 2 which I found playable (at least 33fps) on my 5770 DX11 ultra everything no AA at 1366X720.
When the newer dx11 engines come out at a later point and they are nicely optimized you will kick yourself
okay thnx alot 4 the advice but i have 1 final question...i can get a used sparkle calibre gtx 460 1 gb...it will have no warranty but i will get to check it for 3 days before making payment...now shud i go with the used 460 or a new ice q turbo 6790 with 1 year warranty???is the difference b/w 460 and 6790 substantial enough to sacrifise warranty???
I can not say much about that, the caliber has two fans and will not likely have memory problems like some of the other 460's but this is a personal choice and what you feel comfortable with. The caliber is a well built 460 card and will be quite a bit faster than the 6790 but its a risk not a tech question so its totally up to you.
Like I said that kinda thing is up to you, the value of the 460 is there, providing it is cheaper but if you have no warranty it dies after I told you to get it then its on me, I dont need that anymore than you do.