How does 2 graphic cards function?

[MetricXarrow]

Just curious but how does SLI or running two graphic cards work for instance, say you run one graphic card and it runs a game at 40fps, then say you decide to run two, does it mean you will sit at 40 fps constant, no drop at all since its powered by 2 or does it mean you will booste fps to say 80 since you are running two? how does it exactly work

cheers

 

[JobCreator]

http://en.wikipedia.org/wiki/Scalable_Link_Interface

 

[geofelt]

In theory, you would get 2x the fps.
In practice that does not happen.
Some games do not support dual cards.
Even if they do, there is some overhead in sli so the fps numbers will be less. perhaps 60-85% of 2x.
A problem with dual gpu is that you will get some sort of tearing or stuttering caused by small mismatches in the two cards.
Gameplay is better with a single good card.

 

[MetricXarrow]

In theory, you would get 2x the fps.
In practice that does not happen.
Some games do not support dual cards.
Even if they do, there is some overhead in sli so the fps numbers will be less. perhaps 60-85% of 2x.
A problem with dual gpu is that you will get some sort of tearing or stuttering caused by small mismatches in the two cards.
Gameplay is better with a single good card.

then how do people pull out 120fps on 120fps monitors on like ultra settings on graphic demanding games?

 

[Andrew Buck]

In theory, you would get 2x the fps.
In practice that does not happen.
Some games do not support dual cards.
Even if they do, there is some overhead in sli so the fps numbers will be less. perhaps 60-85% of 2x.
A problem with dual gpu is that you will get some sort of tearing or stuttering caused by small mismatches in the two cards.
Gameplay is better with a single good card.

then how do people pull out 120fps on 120fps monitors on like ultra settings on graphic demanding games?

GTX 780 Ti, SLI those. They can pull it off in SLI, but just dealing with tearing.

 

[geofelt]

They don't.
FRAPS statistics are generated in the pc. What actually gets to the monitor is often something different.
If the monitor receives frames at differing rates from the refresh rate, it will sometimes partially display parts of different images, giving tearing or stuttering.
For that reason, some games are limited to 60fps.
Upcoming G.sync technology shifts the frame presentation timing from the gpu to the monitor, solving many such problems.

 

[Andrew Buck]

They don't.
FRAPS statistics are generated in the pc. What actually gets to the monitor is often something different.
If the monitor receives frames at differing rates from the refresh rate, it will sometimes partially display parts of different images, giving tearing or stuttering.
For that reason, some games are limited to 60fps.
Upcoming G.sync technology shifts the frame presentation timing from the gpu to the monitor, solving many such problems.

They do if they have a powerful setup like 2 780 Ti's. It also matters what you are using to transport the video. Some interfaces such as VGA are limited.

 

[Andrew Buck]

They don't.
FRAPS statistics are generated in the pc. What actually gets to the monitor is often something different.
If the monitor receives frames at differing rates from the refresh rate, it will sometimes partially display parts of different images, giving tearing or stuttering.
For that reason, some games are limited to 60fps.
Upcoming G.sync technology shifts the frame presentation timing from the gpu to the monitor, solving many such problems.

They do if they have a powerful setup like 2 780 Ti's. It also matters what you are using to transport the video. Some interfaces such as VGA are limited.