Other than being pretty power-inefficient, there's really nothing 'wrong' with a GTX465.
It is a more powerful card than a 460, clock-for-clock, and despite a contrary claim above in the thread, the 465 actually does tessellation better
than the 460.
If you can get a 460 for the same price or slightly more, it's worth it since it's cooler/quieter/more efficient, but it's NOT a more powerful/faster card than the 465.
As stock, the two cards basically exchange blows depending on the game you choose, as the 460 has a bit of an advantage in terms of it's clocks, and it's texture-fill capability, but the 465 is more powerful in every other regard.
With each at their max OC's (depending on the individual sample you get of each) the 465 is going to be slightly faster than the 460 in virtually every test. And the SLI scaling is not likely to be significantly different between them if you were to get two.
A lot of people bash the 465 around here, and it IS justified in the sense that it's a pretty inefficient card in terms of the ratio of Watts/FPS. But if you get a good deal on one, it's still a very solid card. In part this is because, in terms of the percentage increase (which is what matters, really) it's one of the very best overclocking cards of all-time. 35-40% OC's (w/voltage bump) on air are pretty common, and the scaling that results from the OC is also exceptional.
In terms of being an upgrade from a 4890, though ... it's not going to make a huge
difference by any means, but I think you'll notice a definite increase in terms of your max playable settings on the tough-to-run games like Metro, Crysis, JC2, etc.
When you look at performance graphs between the two, remember that the 4890 has it's clocks pretty much 'tapped' out of the box, whereas you'll likely be able to squeeze an extra 25% of FPS out of the 465 through OC'ing. Fermi cards also do MUCH better in terms of MIN fps than the 4xxx-series from ATI. Plus you'll get DX11
And two GTX465's in SLI are actually almost equal to a GTX580 (as long as you're not using massive amounts of vram) for just over 1/2 the cost, with WAY more OC'ing headroom.Edited by brettjv - 5/23/11 at 10:07pm