How do they test Graphic cards?

DirectX10/9
in simple words it amplified graphic quality.
theses pictures shows how both directX10 and 9 perform on the 2nd is the DX10 and on the 1st is the DX9






Resolution
No need for any explanation u probably know this already
Higher resolution, Higher stress on graphic card, lower frame rate, Higher Display quality
1024x720
1280×720
1280×1080
1440×1080
1680x1050
1920x1200
2560x1600

Anti Aliasing(AA)

Removes jag from picture see image With AA and No AA
Higher AA x, Higher stress on graphic card, lower frame rate , Higher Display quality
anti aliasing(AA)
No AA
2x
4x
6x
8x
16x

V-sync

Higher stress on graphic card,
Synchronize the Graphic card with the monitor(LCD ,CRT) see image with no v-sync
if ur frame rate is higher then the freq then ur monitor would not be able to catch up to that rate eg:120fps at 60 hz ur monitor will go nuts without v-sync(see the thin line on the picture)

Anisotropic Filtering(AF)

To enchance graphic quality for the distant point

Variables
Experiment 1
Constant:Motherboard,Processor,RAM pretty much everything in a system except the graphic card
Manipulative:Graphic card,Display setting(AA,AF,V-sync)
Responding:Frame per second(FPS)
How do u know what is the range of frame rate considered good?
Higher FPS the better the graphic card is.
10-20FPS-Non playable rate-at this point u better throw away your computer
20-30FPS-playable- u will felt as if something is missing this is TV's refresh rate
30-60FPS-Smooth-above 35 your eye would not notice any different
60-120FPS-super smooth you should crank up the display setting a little to get better quality because Ur computer really deserve it ^^

Results example:
do Notice the AA/AF sign and also the resolution which are located at top and btm