AMD 700 chipsets

The AMD 700 chipset series (also called as AMD 7-Series Chipsets) is a set of chipsets designed by ATI for AMD Phenom processors to be sold under the AMD brand. Several members were launched in the end of 2007 and the first half of 2008, others launched throughout the rest of 2008.

• 1 Development history
• 2 Line-up
  • 2.1 790FX
  • 2.2 790X
  • 2.3 790GX
  • 2.4 785G
    • Codenamed RS880
    • Single AMD processor configuration
    • One physical PCIe 2.0 x16 slot, one PCIe 2.0 x4 slot and two PCIe 2.0 x1 slots, the chipset provides a total of 22 PCIe 2.0 lanes and 4 PCIe 1.1 for A-Link Express II solely in the Northbridge
    • Integrated graphics: Radeon HD 4200
      • ATI Hybrid Graphics and PowerXpress
      • Side-port memory as local frame buffer, supporting DDR2 and GDDR3 chips
      • UVD 2
      • ATI Stream capabilities
    • No 7.1-channel LPCM support^[19]
    • HyperTransport 3.0 and PCI Express 2.0
    • AMD OverDrive
    • Energy efficient Northbridge design
      • 55 nm CMOS fabrication process by TSMC
    • Mainstream hybrid graphics (DirectX 10.1 IGP) segment
    
    
    
  • 2.5 785E
  • 2.6 780G/780V
  • 2.7 780E
  • 2.8 770
  • 2.9 760G
  • 2.10 740G
  • 2.11 740
  • 2.12 Southbridges
• 3 Key features
  • 3.1 Multi-graphics
  • 3.2 AMD OverDrive
  • 3.3 AutoXpress
  • 3.4 Advanced Clock Calibration
  • 3.5 Energy efficiency
  • 3.6 ATI Hybrid Graphics
  • 3.7 I/O acceleration technologies
  • 3.8 Integrated graphics
  • 3.9 "Remote IT"
• 4 Reception
• 5 Northbridge issues(760G, M770, 780x, M780x, 790GX)
• 6 Southbridge issues(SB7x0)
• 7 See also
• 8 References
• 9 External links

Advanced Clock Calibration

Advanced clock calibration (ACC) is a feature originally available for Phenom families of processors, particularly for Black Edition ones, to increase the overclocking potential of the CPU. ACC is supported by the SB710 and the SB750 southbridges, and available through BIOS settings on some motherboards and AMD OverDrive utility.^[43]

It was later discovered that this functionality has the possibility of unlocking the supposedly disabled cores of some Phenom II X2/X3 processors. In normal cases, it is not possible to use or unlock any of those hidden cores because originally those cores were disabled: a technique called "chip harvesting" or "feature binning" used by AMD to sell parts with one or two defective cores which will cause system instability if not disabled.

The following are available through the Advanced Clock Calibration feature:

1. Auto or manual settings
2. Allow separate settings for each of the CPU cores
3. Allowed range: -12% to +12%
4. Possibility of unlocking AMD Phenom II X2/X3, AMD Athlon II X2/X3 and AMD Sempron locked cores / cache. (with BIOS support)

The principle of ACC is not publicly discussed by AMD but some third-party vendors, including ASUS (Core Unlocker)^[44] and Biostar (BIO-unlocKING)^[45] have had it for some time. Gigabyte has added this feature, called CPU Core Control, to many NB785/SB710 boards via BIOS update^[46], and will be including this feature (now called Auto Unlock) in all of their 800 Series boards with the SB850 chip^[47]. On many of the boards, the feature is dependent on BIOS version. 

While NVIDIA also has a similar technology for its nForce 780a motherboards, called NVCC (NVIDIA Clock Calibration) with very similar functionality.

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Northbridge issues(760G, M770, 780x, M780x, 790GX)

• All platforms:
  • Low speed instability with HyperTransport version 3 capable processors. HT3 speeds 1.2 GHz up to 1.6 GHz should not be used, only 1.8 up to 2.2 GHz speeds are safe to be used. HT3 processors operating at 1.6 GHz(Phenom X3 8250e, Phenom X4 9100e and Phenom X4 9150e) will suffer from high retry count on the HyperTransport link which may result in hangs on revision A12 northbridges.
• Windows platform:
  • Microsoft KB959345^[60]

Southbridge issues(SB7x0) Most OSes require patches in order to work reliably.

• Windows platform:
  • Microsoft KB982091^[61]
  • Microsoft KB956871^[62]
  • Microsoft KB953689^[63]
• Linux platform:
  • HPET operation with MSI causes LPC DMA corruption on devices using LPC DMA (floppy, parallel port, serial port in FIR mode) because MSI requests are misinterpreted as DMA cycles by the broken LPC controller^[64]
  • USB freeze when multiple devices are connected through hub (related to AMD Product Advisory PA_SB700AK1)^[65]
  • Erratic behaviour of the HPET when Spread Spectrum is enabled (related to AMD Product Advisory PA_SB700AG2)^[66]
  • Disabling legacy interrupts for SATA disables MSI too^[67]
  • SATA soft reset fails when PMP is enabled and attached devices will not be detected
  • SATA internal errors are ignored because the controller will set Serial ATA port Error when it should not

See also

• AMD 800 chipset series
• AMD 900 chipset series
• nForce 700
• Advanced Micro Devices
• ATI Technologies
• Comparison of AMD Chipsets
• Comparison of ATI graphics processing units