Introduction and Features
If you've been on top of the PC scene for any length of time, you probably know that whether by choice or necessity, AMD has taken a different tact as of late. Whereas the company was all about bigger, faster, and better during the Athlon's heyday, AMD is now more about touting the performance per dollar and value of their products. While they may not have a CPU with the horsepower to compete in the benchmark war with Intel's $1000 behemoths, AMD's affordably priced Phenoms do offer good bang for the buck.
The value conscious mentality that has permeated AMD's recent graphics card and processor launches has also rung true in their motherboard chipset business as well. The 690G and 780G, for example, offered solid feature sets and excellent IGPs, at very affordable prices. And today, AMD continues their recent traditions with the introduction of the 790GX chipset.
The AMD 790GX is a tough product to categorize. It is targeted at value conscious gamers, enthusiasts, and multimedia buffs all at the same time. The block diagram above gives a high-level overview of the chipsets main features and illustrates how each component is connected in the architecture.
As you can see, the AMD 790GX Northbridge is connected to the AM2+ socket through a HyperTransport 3.0 link and it sports and integrated graphics core, along with a flexible PCI Express lane configuration. PATA, 6 SATA ports, HD audio, and 12 USB ports are supported by the SB750 Southbridge. Also, at the bottom of the diagram, a new feature you may not be familiar with, makes its debut--ACC, or Advanced Clock Calibration. More of ACC a bit later.
The AMD 790GX is manufactured at 55nm and features an Integrated Radeon HD 3300 Graphics Processor (IGP) that integrates a DirectX10 compliant Shader Model 4.0 graphics core, a Unified Video Decoder (UVD), two x8 PCI Express 2.0 links or 1 x16 link, HyperTransport 3.0, DVI / HDMI interface, and internal / external TMDS and DisplayPort capability in a single chip. The graphics core is actually identical to the one found in the 780G, but in the 790GX, it is clocked much higher (700MHz) for up to 33% better performance, PowerPlay features have been enahnced to support lower power states, and many boards featuring the 790GX will be equipped with dedicated sideport memory, for increased performance. Of course, the 790GX supports ATI Hybrid CrossFire technology as well, for increased performance or low-power operation.
The AMD SB750 Southbridge communicates with the Northbridge through the A-Link Express II interface. The AMD SB750 offers support for both SATA RAID and IDE drives and it is the key piece in the Advanced Clock Calibration puzzle. In total, the SB750 supports 6x SATA 3.0 Gb/s ports that can be setup in IDE, AHCI, JBOD, RAID 0, RAID 1, RAID 5 or RAID 10 modes, 12x USB 2.0 and 2x USB 1.1 ports, DASH 1.0, 6x PCI slots, HD Audio, IDE, and Serial and Parallel ports.