Conclusion
As we often say, we find that multi-card systems are only of interest on the high end in the way that performances can be improved compared to a single card. This is mainly because the rapid evolution of these cards makes an update of your system with a second mid or entry level solution of little interest compared to its replacement.
This is all the more so that multi-card systems come with a certain number of inconveniences such as higher power consumption, more bulk as well as variable results (sometimes very good, sometimes not) and more bugs than with a single graphic card. Multi-card systems are therefore not yet ready for widespread use. Instead they should be reserved for advanced users that are knowledgeable of the negative aspects and will make sure to always have the latest drivers.
While drivers have strongly evolved as much for Nvidia as AMD (in our opinion SLI and CrossFire being equivalent in this area), they still do not have the same robustness as those with single graphic cards. Little bugs do persist, especially in games that are less in the spotlight.
In the majority of resource heavy games, results are up to expectations. A solution based on two Radeon HD 3870s or GeForce 8800 GTs therefore enables better performances; however this isn’t systematic. The Radeon HD 3870s has results that are slightly disappointing once antialiasing is activated. Also it has performances equal to that of the Radeon HD 3870 X2, which is sometimes more interesting.
For the GeForce 8800 GTs, we also find a limitation in terms of memory in this particular case. For some unknown reason, the GeForce 8 seems either to need more memory than the Radeon HD or else it uses it less efficiently. For this reason, the 512 MB limits performances in certain games in high resolution and with antialiasing activated. Once in SLI, memory use increases again a little more and performances fall instead of improving. This SLI solution is thus recommended for playing in 1920x1200 in complex games, rather than in 2560x1600 with antialiasing and less options or with more simple games.
For those looking for the ultimate performances in high resolutions with antialiasing, they will have to look to the GeForce 8800 GTX or Ultra; however just for the three graphic cards in 3-way SLI this represents a budget as high as 1800 €! It’s an elitist solution that is clearly reserved for wealthier gamers, who have taken the trouble to verify if such a system is adapted to their screen and favorite games because today only a few games will show interesting gains.
