Whats the difference with a computer having 2 graphics card?

[blirt]

Like does it improve graphics or let you choose the different graphics card?

 

[Adiuvo]

When two graphics cards are used it generally improves performance. There are a few games that may have some issues with running cards via Crossfire or SLI (the systems ATI and Nvidia employ for multiple cards) but these games are few and far between. Performance is not typically doubled, but you will notice a large improvement.

Multiple GPUs are usually not the best route to take right off the bat. Personally, I'd consider it better to buy a single high end card and later on when games get more demanding to buy a second of the same card.

 

[FrozenIpaq]

2 graphics cards are used to improve performance by utilizing both cards at once. You'll need identical cards and two PCI-E slots and a large enough case to fit them. You're basically running two GPUs as one which, while doesn't increase the performance 2x, increases it substantially (maybe 1.5x, varies with game and graphics cards).

Nvidia calls their multi-GPU setup SLI while ATI refers to theirs as CrossFire. Both companies are also producing multi-GPU cards (contain two GPUs on one card) which is similar to SLI/CrossFire, just requires less vertical space in a case.

 

[Hardrive]

Spend your money on one card, you'll get much better performance every time.

 

[x3sphere]

Dual GPU these days is only needed if you have a 30" 2560x1600 display or are taking advantage of Eyefinity or Nvidia surround tech.

 

[LocutusEstBorg]

Personally, I'd consider it better to buy a single high end card and later on when games get more demanding to buy a second of the same card.

By the time that happens the current single GPU card is 3x faster than your old one. Like those who got the 7800GTX SLI and got shafted when the 8800GTX came out.

 

[Adiuvo]

It depends on how long you wait I guess. Taking my card for example; a 4890. It can't run Metro 2033 on high at DX10 with 60+ FPS at 1920x1080, but adding a second one can. Going off of some user tests at Tom's Hardware at least, I've never tried personally.

 

[LocutusEstBorg]

All my performance numbers are based on 1680x1050 with 4xMSAA, 16xAF and maxed out settings. Even a GTX480 cannot run Metro 2033 at 30FPS at those settings. Adding a second GTX480 brings it up to speed, but minimum FPS is still in the 20s.