nVidia's 3-way SLI and ATI's Hybrid Crossfire Edition!

NVIDIA 3-Way SLI Performance Review @ Tech Report
The requirements for a 3-Way SLI setup are fairly straight-forward. You can easily build one of these monster configurations yourself and annoy your friends at National Grid and Keyspan in the process too. All you'll need is an 1100 Watt power supply with at least six 6-pin PCI Express power connectors or four 6-pin and two 8-pin connectors, an nForce 680i or 780i motherboard with three full-length PCIe slots, a fairly roomy case with good airflow, Windows Vista and the right NVIDIA driver to support 3-Way SLI. Incidentally, NVIDIA has noted that AMD-based 3-Way solutions are forthcoming. We'll take a look at what a 3-Way SLI-enabled system from the folks at MainGear Computers looks like next.

NVIDIA 3-Way SLI Technology Review - 8880 Ultra x 3 @ PC Perspective
You can see that this bridge uses six connections to the graphics boards, two to each card. You might then wonder what happens to all the NVIDIA GeForce cards that do NOT have two SLI bridge connections on them. The answer: you don’t get 3-Way SLI. This technology is being limited to users or buyers of 8800 GTX and 8800 Ultra graphics boards as they are the only ones that have to dual bridge connections on them. This is more than somewhat disappointing to our readers I would guess simply because most of them don’t have one of those cards. With the success of the 8800 GT and new GTS 512MB cards I would have thought NVIDIA would be support 3-Way and maybe even 4-Way SLI to help get users to buy a second and third $200-$350 graphics board, but that isn’t the case.

Nvidia 3-way SLI on nForce 680i @ Bit-Tech
Over the past couple of days, we were given access to the driver in order to get an idea of how well 3-way SLI is shaping up. Nvidia has been quite open by saying that 3-way SLI will be shown in its best possible light on its next-generation platform, whose launch isn’t too far away, but in the interests of giving its current customers an upgrade path, it has enabled 3-way SLI on all existing nForce 680i SLI motherboards. Considering the fact that Intel’s 45nm processors will not function properly in any of the nForce 680i SLI motherboards available—something that Nvidia says was out of its control—it’s good to see that Nvidia is at least offering upgrades for existing customers where it can.

AMD Hybrid CrossFire Preview: Making Two Slow GPUs, Not So Slow @ Anandtech
Hybrid CrossFire requires two components: a Hybrid CrossFire chipset and supporting graphics card. The chipset part is the forthcoming RS780, a successor to the AMD 690G and an integrated graphics version of the AMD 790 chipset. The RS780 will ship with an integrated RV610 graphics core, the heart of the ATI Radeon HD 2400 Pro. AMD insists that the RS780G's integrated graphics is fundamentally unchanged from the Radeon HD 2400, so we should expect a similar level of performance (AMD estimated 3 - 4x the 3DMark '06 score of the 690G, but gave no information on actual gaming tests).

AMD Introduces Hybrid CrossFire - 780G and Radeon HD 2400 @ Legit Reviews
When it comes to performance the Radeon HD 3450 isn't going to dominate any games, but it does score a respectable ~1650 points in 3DMark 2006 on the test system powered by a 2.2GHz AMD Phenom processor. If you enable Hybrid CrossFire the score in 3DMark 2006 jumps up to ~2660 points, which is a boost of over 60%. We didn't get a chance to see the ATI Radeon HD 3470 graphics card in action, but AMD said it should score over 3000 points when run in Hybrid CrossFire on 3DMark 2006. AMD let us try out Call of Duty 4 at 1024x768 with decent quality settings on the system pictured here and we were seeing 20-50 frames per second Hybrid CrossFire enabled.