How to compare graphics cards by reading the specs?

Hi,

Please don't answer by saying look at benchmarks, that's really not what I'm looking for.

What I want to know is. How can you tell how good it is by looking at the specs?

I used to compare the fillrates... the higher the fillrate, the better the card but I'm starting to understand that technically, fillrate doesn't always relate to the cards performance. How can a card with a lower fillrate be a better performer than a card with a lower fillrate? It's true because you can see it in benchmarks.

So, what I'm asking is, please could somebody explain how to tell which cards are good?

For example:

Gfx card 1 has 500mhz core, 1000mhz shader and 1000mhz memory.. it has a fillrate of 2gt/s..
Gfx card 2 has 600mhz core, 1200mhz shader and 1200mhz memory.. it has a fillrate of 1.6gt/s..

How can card 1 have a better fillrate??? Surely card 2 would have a better fillrate as its specs are higher?

Also that brings me onto benchmarks... card 2 may perform better in benchmarks..

I just don't understand it.

Please can anyone explain how you can determine how good a card is by reading the specs.. just for the sake of being able to compare them???

Cheers!

 

Depends on the architechture of the card, is the gfx 1 same card series with gfx 2?