how do i know which ATI or Nvidia graphic card are good? is there a way to know?

ATI and Nvidia use different numbering schemes, but the same basic principle: A card model number is broken down into two parts. The first digit tells you the card series or family- that's simply how new the card is.

For ATI Radeon: the 5000 series cards are the latest bunch (which were first introduced in mid-2009), the 4000 series cards are the previous generation from 2008, the 3000 series were around in 2007 and the 2000 series before that.

For Nvidia's Geforce 6000 through 9000 series cards it's the same story. However, after the 9000 series cards Nvidia decided to rename things completely, coming out with their 200 series and later, 400 series cards (These models only have 3 digits)

The thing to remember is that it's NOT simply "the higher number is better", the first digit only tells you how recent a card is, not it's level of performance. The digits AFTER the first one tell you that.

For Nvidia- serious gaming cards ended in 800 or higher, entry-level gaming cards ended in 600 and anything below that was too slow for gaming, although fine for regular work.

It's kind of like the model year on automobiles. Chevy introduces new cars every year, but just because a car is newer doesn't mean it's better. A 2008 Corvette is still much faster than a 2010 Cobalt. It's the same thing with graphics cards- every series includes models ranging from $40 budget cards to high-performance gaming cards costing hundreds of dollars.

Because technology tends to improve each year, later model cards of the same level tend to be a little better than the models they replace. For example, the GeForce 7600GT is better than the 6600GT, a 9500GT is better than an 8500GT etc.

The last digits are MORE important than the first one! When the last 3 digits are the same, newer cards are almost always better than earlier models. But a GeForce 8800 is better than a 9600 or 9500- even though it's older it's a higher performance model. By the same token, a GeForce 7600 is superior to an 8400 or 8500.

The two-letter suffixes on Nvidia 6000-9000 series cards also having meaning.

LE = worst version of a card

GS = slower, cheaper version of a card

GT = standard version of a card

GTS = higher-clocked, faster version of a card

GTX = fastest version of a card

This is a very simplified summary. There's more to it, especially since Nvidia completely re-did their numbering system. They renamed the 9800GTX+ to the GTS 250, and their other cards fell into line. The GTX 260 is higher-end, while the GT240 is basically equivalent to the 9600GT, the GT220 is an improved 9500GT, the G210 is about equivalent to the 9400GT.

With ATI Radeon cards it's similar- the last 3 digits tell you how fast a card is. The Radeon 4850 is faster than a 4670 which is faster than a 5450... 850>670>450, regardless of the card series.

Now that's only true up to a point... once the numbers go above 750, newer Radeon cards start blowing past earlier models, even higher-numbered ones. For example, the Radeon 4770 outperforms the 3870, the 5830 outperforms the 4890 etc.

Here's a hierarchy chart from Tom's Hardware showing where most cards from ATI and Nvidia (both current and discontinued) rank:

http://www.tomshardware.com/reviews/geforce-gtx-46...

Videos on Youtube that show benchmarks.

And the graphics card with the best FPS is a good gpu.

And yes the higher number the better those are the most latest.

but don't get confused with the GTX9800 and the GTX465 the 9800 may look greater, but the GTX465 is better only if you have good computer specs that is.

And I'm a beginner too, just got in to computers.

I currently have the ATI Radeon HD 5570 it's pretty good.