Whats better 2 Ati4850 SLI or one 4850X2?

[motoadve]

Whats better 2 Ati4850 SLI or one 4850X2?
The difference in price is $20, so I go with what is better.

 

[jaguarskx]

Read the following article which will help answer your question.

http://www.xbitlabs.com/articles/video/display/radeon-hd4870-crossfire.html



Here's two chart from the conclusion section:

Summing it up, we guess that building a graphics subsystem out of two Radeon HD 4870 cards may make sense for people who already have one such card but do not have a 30-inch monitor with a resolution of 2560x1600. Moreover, the bulky 4870 X2 and GeForce GTX 280/260 may not be installed in small system cases and the Radeon HD 4870 may make a good alternative then.

Of course, the Radeon HD 4870 CrossFire subsystem is less easy to install than a single card. It also requires a mainboard with two PCI Express x16 slots and support for ATI CrossFire technology. But CrossFire is now supported by a huge number of mainboards based on AMD’s and Intel’s chipsets, so this shouldn’t be a problem.

 

[Maziar]

First of all its not 2 ATI HD 4850 in SLI,its 2 HD 4850s in CrossFire (CrossFire is for ATI).
To answer your question,go for single HD 4850X2 because as jaguarskx posted a good benchmark and according to all the reviews around the web,1 HD 4870X2 performs 0-15% better than 2 HD 4870s (Its the same for comparing 1 HD 4850X2 and 2 HD 4850s) and 1 HD 4850X2 has less power consumption and requires 1
PCI-E slot.