Want to buy a graphic card

[jelson]

OK, 1st things first. There is a Go-To for this sort of question at Tom's Hardware. Every month, there's an article about the best Graphic card for the $. The link for Dec 2011 is

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. The most important page for you is the last one where you'll find Graphics Card Hierarchy Chart .

Here is a resource to help you judge if a card is a good buy or not. The graphics card hierarchy chart groups graphics cards with similar overall performance levels into tiers. The top tier contains the highest-performing cards available and performance decreases as you go down the tiers from there.

You can use this hierarchy to compare the pricing between two cards, to see which one is a better deal, and also to determine if an upgrade is worthwhile. I don’t recommend upgrading your graphics card unless the replacement card is at least three tiers higher. Otherwise, the upgrade is somewhat parallel and you may not notice a worthwhile difference in performance.

You're find their ranking is as follows:
HD 6770 : 7th Tier
GTX 550 Ti : 7th Tier
GTS 450 : 8th Tier
HD 5670 : 10th Tier

So, the 550 Ti & 6670 are about the same. And the 5670 is definitely a step below them.

So, the next question is what are you going to use it for? Gaming only? Multiple monitors? (nVidia's & ATI's desktop control apps have some differences)

If you need your GPU to do hardware assistance for like video encoding, then definitely go with nVidia Lots of apps have nVidia CUDA support but only a few apps currently do ATI Stream.

Once you have it narrowed down, then you can look at manufacturers. Personally, I first do research at NewEgg (user reviews) and then the forums at Tom's to double-check my conclusions. Hope this helps.

P.S. Newegg & Amazon are the online retailers I trust most. And Newegg frequently has sales.

RE: power supply ==> Buy the best quality PSU you can afford; it's the one thing you never want to cut corners on. A cheap power suppy can destroy an entire system.

Corsair, most Antecs and Seasonic are among the best out there. I took a very long time researching power supply models until I settled on a Corsair TX650. I really wanted a modular unit, but my budget wouldn't allow for modular + top quality.

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is a great place to start researching power supplies.