Some time ago, AMD introduced very good 780G integrated chipset that set new standards in multimedia and 3D performance levels of integrated graphics cards. AMD RS780 was, at first, made in two versions: 790GX and 780G.

AMD 790GX chipset, besides Integrated Graphics Processor (IGP) at full 700MHz, introduced new south bridge: SB750. This new south bridge supports ACC (Advanced Clock Calibration) which allows calibration of clock signal between CPU cores and south bridge. This technique was used to achieve higher stable overclock frequencies of earlier Phenom II CPU generation based on 65nm manufacturing process. Latter ACC was used as a way to unlock cores on dual and triple core Phenom II CPUs that were disabled by AMD. Since ACC can calibrate signal for each core you could activate disabled cores and get a triple or quad core CPU from dual or triple one. In addition, AMD 790GX chipset supported Sideport memory and PCI-Express CrossFire multi GPU systems.

AMD 780G chipset, on the other hand, had, as an option, 64 or 128MB or Sideport DDR2 RAM that is, btw, used to speed up integrated graphics card and to decrease load on memory bus and refreshing of integrated graphics frame buffer. For end-users most important feature of AMD 780G  chipset was its ability to play HD video thanks to present hardware acceleration in form of UVD (Unified Video Decoder). UVD has support for H.264/AVC and VC1 video decoding acceleration. Because of these features AMD 780G is one of the best solution when it comes to building your own custom HTPC, because it can be used for playing video material on your HDTV.

AMD 785G

If you expected that AMD 785G is something spectacularly new, we will bring you only disappointing news. Actually, AMD 785G can be positioned in between 780G and 790GX.

Of course, there are some new features, such as: SB710 south bridge. New SB710 is actually SB700 with ACC support. Main difference between SB750 and SB710 is lack of support for RAID 5 in SB710. All other features are present including AHCI mode and NCQ (Native Command Queuing). AMD 785G south bridge (SB710) also has new Radeon HD 4200 GPU (RV620) that has DirectX 10.1 support. Old HD 3200 (RV610) has “only” support for DirectX 10.0 API. Rendering and shader unit are the same, which can be also sad for manufacturing process: 55nm. Even frequency of new GPU is the same as on AMD 780G: 500MHz. Support for HDMI 1.3 is also implemented along with support for 48-bit color. Thanks to this support for Dolby TrueHD and DTS-HD Master Audio is also present. AMD 785G and its SB710 does not support more than 6 audio channels so 5.1 surround is maximum that can be expected from this chipset.

AMD 785G also introduces new UVD 2.0 that, besides H.264/AVC and VC1, supports dynamic contrast control, picture-in-picture acceleration, HD Flesh Tone Enhancement and HD Color Vibrance technology. Compared to AMD 780G, new AMD 785G has better power management thanks to which GPU can dynamically change its frequency and decrease power consumption and thermal dissipation. ATI Stream Technology is AMDs GPGPU solution that is compatible with all GPUs from 4000 family and it can be used to accelerate audio and video conversions.