AMD 780G Performance and Overclocking Preview

Ever since it was launched last year, we’ve been huge fans of AMD’s 690G chipset. The chipset delivered best-in-class integrated graphics performance, outrunning rival chipsets from Intel and NVIDIA. In addition 690G boasted a solid feature set, the chipset supported dual digital display output (including native support for HDMI and dual-link DVI) with HDCP, ATI Surroundview and Avivo, as well as all the I/O functionality you could possibly want from an integrated platform. The chipset was also built on TSMC’s 80-nm manufacturing process, allowing it to consume very little power and thus generate minimal heat. This made the 690G ideal for use in home theater PCs.

At the heart of the 690G was ATI’s Radeon X1250 integrated graphics processor. Largely derived from ATI’s Radeon X700 family on the desktop, the X1250 IGP featured a 4-pixel shader architecture, with four texture units and a 400MHz clock speed. The GPU lacked vertex shaders, offloading that functionality to the CPU instead, but this was typical of all chipsets of that era. Where it stood out was its versatility as a platform: its IGP performance was excellent, as well as its display flexibility, and it was priced to move.

Then Intel released their next-generation, Bearlake-G, G35 chipset. On paper, G35 had a couple of features going for it that weren’t offered by AMD-690.

Most notable was DirectX 10 support. Its GMA X3500 graphics core was the first to offer full support for Microsoft’s latest API. While any hardcore gamer knows that DX10’s adoption rate has been slow at best to date due to its performance (turning on DX10 features in many games drastically saps performance) and lack of a real killer game release, to a system builder or OEM, this is a really important check mark feature that G35 boasts over AMD-690. The G35 chipset also offers hardware-based vertex shaders.

The 780G chipset is AMD’s answer to G35. The chipset is built around a brand new IGP supporting DirectX 10 graphics functionality, PCIe 2.0, HyperTransport 3, and one interesting new feature known as Hybrid Graphics. With Hybrid Graphics you can combine the integrated graphics found in the 780G chipset with a Radeon HD 3450 or 3470 discrete graphics card for more performance. Think of it like CrossFire, but for chipsets. We took a look at Hybrid Graphics performance last week and found the IGP+3450 combination was capable of delivering a performance improvement of 2X in certain cases (Company of Heroes performance more than doubled actually)!

780G is also based on TSMC’s smaller 55-nm process, allowing it to consume less power than 690G despite its increased functionality. AMD claims idle power consumption of the IGP is just 0.95W! The 780G chipset also consists of a new SB700 South Bridge. This new chip is mainly an evolutionary upgrade over AMD’s previous SB600 South Bridge, integrating a revamped USB controller with support for two additional USB 2.0 ports.

Let’s go over the new chipset in more detail…