Http://www tomshardware com/forum/276881-33-5750-asus-dark-knight

[Riyaadt]

Hello im interested in a GPU, which is better Nvidia GTX275 or sapphire Ati Radeon 5770 512MB /

 

[Anik8]

ATI 5770 offers DirectX 11 and is a bit cheaper than GTX275 and provides shader model 5.0(latest),tesselation,HDR Texture compression which GTX 275 doesn't.This card has the same features one will find in 5800 series but a slightly reduced performance,which means you can overclock this card to quite an extent.

On the other hand although the GTX 275 offers directx 10 only.. still this card is built upon the 55nm GPU the same one present in GTX 285 and is faster and more powerful than the HD 5770 and can deliver similar performance like a GTX 285.Moreover this is a quiet and cool card despite the power it delivers unlike gts 250 and 9800gtx.Plus the card comes with a minimum 893 VRAM memory.

 

[dalta centauri]

The 5770 competes against a 4870/260.
A 460 would benefit you as it competes(beats) the 5770 with the same features and the normal Nvidia 3d/physx support.

If you need multi monitor setups go with either the 5850/70 or two 460/470's.