AMD 700 chipset series


The AMD 700 chipset series 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.

Development history

The existence of the chipsets was proven in October 2006 through two hardware websites in Chile and Spain which posted the leaked slides of an ATI internal event, "ATI chipset update". In the slides, ATI has shown a series of RD700 series chipset logics codenamed RD790, RX790, RS780 and RS740 respectively. A SB700 southbridge was also mentioned in the event. The 790X chipset was spotted in Computex 2007, exhibited by ASUS. The RS780D was first reported by HKEPC while the RX780H was first seen on ECS internal presentations.
After the acquisition of ATI Technologies, AMD started to participate in the development of the chipset series. And as a result, the first performance and enthusiast segment chipsets products under the AMD brand, the 790FX, 790X and 770 chipsets were launched on November 19, 2007 as part of the Spider codenamed desktop performance platform. The 780 chipset series, first launched in China on January 23, 2008, and released worldwide on March 5, 2008 during CeBIT 2008, mobile chipsets were released on June 4, 2008 during Computex 2008 as part of the Puma mobile platform and the 790GX chipset was released on August 6, 2008, while some other members released at a later date in 2008. The 785G was announced on August 4, 2009.

Line-up

790FX

Besides the use of SB600 southbridge for earlier releases of several members in late 2007, all of the above chipsets can also utilize newer southbridge designs, the SB700, SB710 and the SB750 southbridges. Future server chipsets will also utilize the server version of the southbridges. Features provided by the southbridge are listed as follows:

SB700

Multi-graphics

The ATI CrossFire X technology supports multiple video cards to be connected to enhance the visual display and 3D rendering capabilities of the system, using AFR mode and/or scissor mode. Alternatively, systems with multiple video card CrossFire X setup will support multiple display monitors up to eight.
For the AMD 790FX chipset, the CrossFire X technology allows up to 4 video cards to be connected, made possible as the chipset supports four physical PCI-E x16 slots. The PCI-E lanes can be configured for 4 slots at x8 bandwidth or 2 slots at x16 bandwidth. Reports indicate 2.6 times the performance with triple-card CrossFire than that of a single card, and more than 3.3 times the performance increase for quad-card CrossFire. Gigabyte have revealed in a leaked product presentation that the four card CrossFire X setup does not require CrossFire connectors; the data will be exchanged among the PCI-E slots which is monitored and controlled by Catalyst drivers.
For the performance segment, CrossFire on the AMD 790X chipset has two physical PCI-E x16 slots with one operating at x8 bandwidth, supporting up to four display monitors.
Multi-graphics is also supported for the 790GX IGP chipset, named as Hybrid CrossFire X.

AMD OverDrive

Another feature is AMD OverDrive, an application designed to boost system performance through a list of items in real-time, without a system reboot, as listed below:
The application will support all members of the AMD 700 chipset series, including the 740 series chipsets which are aimed at value markets, and AMD processors including Phenom and Athlon 64 family of processors, but due to architectural limitations, independent clock frequency settings for different processor cores will not function on Athlon 64 family of processors.

AutoXpress

The AutoXpress technology is a set of automatic system tuning features to enhance system performance, which were revealed by members of ChileHardware when investigating the BIOS for AMD 790FX, 790X and 770 chipsets. AutoXpress will be available on AMD 790FX chipset, with AMD 790X and AMD 770 chipsets implementing a subset of all the features. The AutoXpress technology is similar to the LinkBoost capability presented on NVIDIA nForce 500/600 chipsets.
The feature must be enabled via BIOS, options appeared in the BIOS includes ON/OFF/Custom, which choosing the "Custom" option will open up three further options, namely "CPU", "XpressRoute" and "MemBoost" with ON/OFF options, and ON as default. Details about the AutoXpress features are listed as follows:

Advanced Clock Calibration

Advanced clock calibration 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.
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.
The principle of ACC is not publicly discussed by AMD but some third-party vendors, including ASUS and Biostar have had it for some time. Gigabyte has added this feature, called CPU Core Control, to many NB785/SB710 boards via BIOS update, and will be including this feature in all of their 800 Series boards with the SB850 chip. 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 with very similar functionality.

Energy efficiency

One of the major focus of the chipset series is the energy efficiency of the chipsets. The need for energy-efficient chipsets have risen since chipsets starts including more features and more PCI Express lanes, to provide better system scalability by using PCI-E add-on cards.
But one issue is that chipset circuitries were usually made on a larger fabrication process nodes compared with the latest CPU process node, making recent chipsets consume more and more power than their predecessors. Recent examples including the Intel X38 chipset Northbridge, labelling 26.5 W TDP with a maximum idle power of 12.3 W, which results in the usage of integrated heat spreader design over the chip to help heat spread evenly, with ASUS even adding water cooling block directly on top of the heatsink of the X38 Northbridge as a part of the motherboard heatpipe system. Although the aforementioned figures may be small compared to the TDP figures of a performance CPU, there is a growing demand for computer systems with higher performance and lower power consumption. While Intel focuses only on the energy efficiency of its processors, NVIDIA's nForce 780i chipset requires an overall power consumption of 48 W with the northbridge, southbridge and the nForce 200 PCI-E bridge.
In response to this, all discrete northbridges of the chipset series were designed on a 65 nm CMOS process, manufactured by TSMC, aimed at lowering power consumptions of chipsets. According to internal testing and various reports, the Northbridge of the AMD 790FX chipset runs at 3 W when idle, and maximum 10 W under load, nominal 8 W power consumption, the northbridge was seen on reference design of the AMD 790FX chipset with single passive cooling heatsink instead of connecting to heat pipes which are frequently used on current performance motherboard offers, the chipset on the whole consumes nominally less than 15 W.
The integrated graphics northbridges were also benefited, as most of the IGP northbridges were made on 55 nm process manufactured by TSMC with the inclusion of ATI PowerPlay technology, allowing dynamically changing the core clock frequency to minimum 150 MHz. The 780G Northbridge, sporting DirectX 10 support, consumes only 11.4 W on full load, 0.94 watt when idle. This is also smaller than the TDP figures of the Intel G35 chipset Northbridge at 28 W with the maximum idle power of 11 W.

ATI Hybrid Graphics

The ATI Hybrid Graphics technology applies to all or some of the integrated graphics chipsets of this chipset series, technologies including Hybrid CrossFire X, SurroundView and PowerXpress. Reports confirmed that the 790GX IGP chipset will be able to handle dual video card and IGP as a CrossFire X setup. Hybrid Graphics are only available with 24xx, 34xx, & 42xx model ATI graphics cards.

I/O acceleration technologies

All chipsets paired with either SB700, SB710 or SB750 southbridge will support two I/O acceleration technologies, as listed below:

Hybrid Drives

The southbridges also support hybrid drives via SATA or supported ATA ports, which is compliant with the requirements of the Windows ReadyDrive technology, which is basically a conventional hard drive with an embedded NAND flash module.

HyperFlash

The HyperFlash, basically a NAND flash module on a card, originally planned as a device connected to the supported IDE/ATA 66/100/133 channel, to speed up system performance through the Windows ReadyBoost and Windows ReadyDrive functionality.
A HyperFlash module consists of two parts, the first part is a HyperFlash memory card which are flash memory chips on a small PCB with contacts similar to SO-DIMM modules. The other part is a flash controller on an ATA connector, with similar latches/socket ejectors as SO-DIMM sockets. The HyperFlash memory card is inserted into the flash controller and then directly plugged into the motherboard ATA connector. The memory chips used on the HyperFlash memory card will be Samsung's with maximum four-die configuration, running at 83 MHz frequency, providing a bandwidth of 108 MB/s on a 16-bit bus width. Since the flash controller is designed to be compatible with ATA pin-out definitions and is designed by Molex, this allows OEMs to produce their own brands of HyperFlash modules while at the same time providing maximum compatibility between HyperFlash modules.
Three variants were reportedly be available for HyperFlash modules, with capacity of 512 MiB, 1 GiB and 2 GiB respectively, with expected DVT samples in November 2007 and mass-production expected in December 2007 and official motherboard driver support planned in February 2008. However, it was reportedly cancelled.

RAIDXpert

The RAIDXpert is a remote RAID configuration tool, for changing the RAID level of the RAID setup connected via SATA 3.0 Gbit/s ports, including RAID 0, RAID 1, and RAID 0+1.

Integrated graphics

Some of the members of the AMD 700 chipset series, specifically the 780 and 740 family of chipsets and the 790GX chipset, have integrated graphics onboard, as well as supporting hardware video playback acceleration at different levels. All IGP northbridges are pin-compatible to each other and even predecessors, to lower the product cost for each PCB redesign due to pin incompatibility and maximize the product lineup. These IGP features are listed below:

"Remote IT"

For the enterprise platform, the "Remote IT" technology was reported to be released by the end of 2007 or early 2008. The platform composed of an AMD 780V chipset with an SB700 southbridge, and chips from Broadcom, Realtek and Marvell. It was reported to have incorporated the Broadcom BCM5761 managed NIC controller with Intelligent Platform Management Interface 1.5 manageability standard, together with DASH 1.0 specification support of the SB700 and SB750 southbridges, and reported support additional management and security technologies such as IDM and TPM 1.2.

Reception

In a comparison against the GeForce 8200, Anandtech considered the 780G "a better balanced chipset offering improved casual gaming performance, equal video quality, similar power requirements, greater availability, and better pricing." The 8200, however, was preferred as a single-purpose HTPC solution. Both chipsets were considered superior to Intel's G45/X4500HD, which was cited for a lack of driver quality and features, and a higher price.

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

Most OSes require patches in order to work reliably.