Introduction
The end may be near for discrete chipsets, at least if NVidia has its way, but does this mean an end for performance motherboards ? Often considered the bane of performance computing, integrated graphics will soon be found on all of the firm’s products. If that idea sends chills down your spine, NVidia is hoping that today’s launch will change your mind.
Welcome to the era of Hybrid SLI, where mainstream discrete cards are to receive a small performance boost from an integrated controller, while systems with high-end graphics benefit from increased energy efficiency. Under the banner of GeForce Boost, GeForce 8400GS and 8500GT graphics cards benefit from the 3D power of NVidia’s onboard graphics processor, by sharing the workload. At the other end of the market, NVidia’s HybridPower technology allows onboard graphics to take over display needs in 2D applications, powering down 9800GTX and 9800GX2 processors when 3D performance isn’t needed. These technologies are mutually exclusive, and while NVidia has promised expanded support for Hybrid SLI in upcoming drivers, the company isn’t prepared to state which technology will be applied to any specific model.
AMD’s Socket AM2+ might seem an unlikely candidate for high-end platform development, but NVidia had let its AMD-compatible product line languish so long that they had to either act quickly upon this market or watch it slip away. For AMD’s part, improvements in its Phenom line have at least made these a viable performance value.
The 780a SLI Northbridge is actually a single-device chipset, with all but three of its PCI-Express pathways re-routed to the nForce 200 PCI-Express 2.0 bridge. The diagram shows support for three x16 graphics cards, but nForce 200 only supports 32 pathways. Three-way SLI configuration requires one of the x16 slots to share its pathways in dual x8 mode.
NVidia lists a broad range of cutting-edge features for its 780a SLI chipset, but Hybrid SLI is the only one not seen before in the company’s products. Even the nForce 200 bridge is carried over from the company’s previous Intel parts, and the new-found support for DDR2-1066 memory is a feature of the latest AMD Phenom processor’s on-die memory controller.
NVidia wouldn’t be happy unless we at least mentioned the 780a’s compatibility with ESA, the firm’s "open source" monitoring, reporting and adjustment utility for controlling clock speeds, component voltage, and cooling across multiple system devices. But today’s focus will be on the chipset’s unique feature, Hybrid SLI, and the performance or energy efficiency advantages it offers.