A GTX 650 Ti would get about the same credits as two GTX285's combined, but would use 200W less power.

Palamedes, if you plan to crunch for several months or more then selling the 285's and buying a 650Ti (or better) would make sense; the power savings would pay for the new card in a few months and you would still have a newish card which is somewhat future proofed, cheaper to run and worth more.

For crunching it makes sense to buy cards several months after their release (when the prices drop) and replace them about every 2 years or so (while they still have some value).
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Agreed - it really depends on your electricity cost. If it's very low you could still run them for some time. And you could use them for POEM, running 3 - 4 WUs per GPU. There the obviously still consume more power than modern cards, but should still be able to achieve ~500k RAC with a Quad Core host and PCIe 2. That's half as fast as top end cards, i.e. still pretty good. The reason why the old cardss are still doing so well is because they're limited by PCIe 3 over there (which is really unusual).

MrS
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