Guru3D uses the following games in their test suite, COD-MW, Bad Company 2, Dirt 2, Far Cry 2, Metro 2033, Dawn of Discovery, Crysis Warhead. Total fps (summing fps in each game @ 1920 x 1200) for the various options in parenthesis (single card / SL or CF) are tabulated below along with their cost in dollars per frame single card - CF or SLI:
$155.00 460-768 MB (314/592) $0.49 - $0.52
$155.00 6850 (371/634) $0.42 - $0.49
$190.00 6870 (434/701) $0.44 - $0.54
$250.00 6950 (479/751) $0.52 - $0.67
$285.00 6950 Frozr OC (484/759) $0.59 - $0.75
$240.00 560 Ti (455/792) $0.53 - $0.61
$335.00 6970 (526/825) $0.64 - $0.81
$240.00 560 Ti - 900 Mhz (495/862) $0.48 - $0.56
$335.00 570 (524/873) $0.64 - $0.77
$500.00 580 (616/953) $0.81 - $1.05
$725.00 6990 (762/903) $0.95 - $1.61
$700.00 590 (881/982) $0.79 - $1.43
Based upon the above, if getting and staying w/ a single card, the 6950 flash to 6970 is the way to go w/ single card ... if a 2nd card is in the plan, I'd do 560 Ti's (900 Mhz) ... last week two 560 Ti (900Mhz) wuda cost ya $430, but now lowest is $480.