In 1998, 3dfx released Voodoo's successor, the popular Voodoo2. The Voodoo2 was architecturally similar, but the basic board configuration added a second texturing unit, allowing two textures to be drawn in a single pass.
A problem with the Voodoo2 was the fact that it required three chips and a separate VGA graphics card, whereas new competing 3D products, such as the ATI Rage Pro, NVIDIA RIVA 128, and Rendition Verite 2200, were single-chip products. Despite this shortcoming, the card's dithered 16-bit 3D color rendering limitation, and an 800×600 resolution limitation, no other manufacturers' products could match the smooth framerates that the Voodoo2 produced. It was a landmark (and expensive) achievement in PC's 3D-graphics. Its excellent performance, and the mindshare gained from the original Voodoo Graphics, resulted in its success. Many users even preferred Voodoo2's dedicated purpose, because they were free to use the quality 2D card of their choice as a result. Some 2D/3D combined solutions at the time offered quite sub-par 2D quality and speed.
The arrival of the NVIDIA RIVA TNT with integrated 2D/3D chipset would offer minor challenge to the Voodoo2's supremacy months later.
SLI
The Voodoo2 introduced Scan-Line Interleave (SLI) to the gaming market. In SLI mode, two Voodoo2 boards were connected together, each drawing half the scan lines of the screen. For the price of a second Voodoo2 board, users could essentially double their 3D throughput. A welcome result of SLI mode was an increase in the maximum resolution supported, now up to 1024×768. Despite the high cost and inconvenience of using three separate graphics cards, the Voodoo2 SLI scheme was clearly the pinnacle of gaming performance at the time.
SLI capability was not offered in subsequent 3dfx board designs, although the technology would be later used to link the VSA-100 chips on the Voodoo 5.
Having since acquired 3dfx, NVIDIA in 2004 reintroduced the SLI brand (now for Scalable Link Interface) in their GeForce 6 Series. ATI Technologies has also since introduced its own multi-chip implementation, dubbed "CrossFire". Although Scalable Link Interface and Crossfire operate on the original SLI principle, the algorithms used are now totally different.
