Wednesday, December 19, 2007

20/12: Gigabyte 780SLI-DS5 - a Motherboard Based on the NVIDIA nForce 780i SLI Chipset

Gigabyte kindly sent us its motherboard on the new chipset from NVIDIA before the official announcement. Company engineers were forced to try various cooling solutions to find the best choice because of problems with chipset cooling (see below). So probably even our review sample was not of the final design. It was very interesting to examine a motherboard on the new top-end chipset, the nForce 780i SLI.



The most interesting element of the motherboard is its cooling system, of course. The nForce 680i SLI was notable for its "hot temper", so there is nothing surprising about the fact that its descendant with an additional nForce 200 bridge, which is also hot, breaks all records here. A large heat sink covers the north bridge and nForce 200. One heat pipe connects it with a heat sink on field-effect transistors in the CPU power circuit. The large heat sink gets very hot - I really burned my finger, when I tried to evaluate its temperature by touch. The south bridge also gets very hot, so a small heat sink on this bridge looks mocking. We do not reproach Gigabyte engineers here: it's impossible to make this heat sink wider (because of large on-board components), and a higher heat sink would have blocked expansion cards.

It's a no-win situation. We can only note that the heat sink of the final design for the south bridge will be smaller, but it will be connected to the heat sink on the north bridge with a heat pipe. However, it will not improve the situation radically, in our opinion. In this case users will have to give up the idea of passive cooling. The reference motherboard from NVIDIA proves that we are right. Heat sinks on the south and north bridges are connected with four heat pipes, but the north bridge is still equipped with a big fan. Anyway, you'll have to provide good ventilation inside your system unit, if you decide to buy a motherboard on nForce 780i SLI.

There are no other surprises. All connectors on the motherboard are spaced apart not to interfere with each other as you plug cables. We'd like to mention the layout of SATA ports: all six ports sit at the nearest edge of the PCB, grouped into vertical couples. It's clear that three graphics cards installed in the 3-way SLI mode will deprive the motherboard of all expansion slots - this tendency is pardonable for a top SLI product.

The 6-phase switching voltage regulator of the processor uses two field-effect transistors per phase and high-quality FPCAP polymer capacitors from Fujitsu with low ESR. Motherboard dimensions - 305x245 mm (full-sized ATX), it's mounted with nine standard screws, all corners are firmly fixed. We don't have information about other Gigabyte motherboards on 780i/750i SLI yet. So we cannot say whether the company will offer similar products on the same or similar PCB. Theoretically, we can expect a more expensive model in the DQ6 family.

System monitoring (ITE IT8718F-S, BIOS Setup info)

- Voltages on CPU, memory, +3.3 V, and +12 V (only indication of correct values!)
- Rotational speed of three fans, two of them offer automatic fan speed control
- CPU and board temperatures (by the corresponding embedded sensors).
- Automatic speed control of two fans is limited to the choice of a control type (depending on a given model - 3 or 4 pins) the choice comes down to reducing voltage or skipping cycles) as well as the Intel QST option (using a digital temperature sensor in new Core 2/Extreme processors) instead of the classic scenario. But you cannot specify any thresholds.

- Fan modes can be fine-tuned with EasyTune[5] for Windows.


Onboard ports, sockets, and connectors

- Socket 775, support for processors with 800-1333 MHz FSB, including future products with the Penryn core
- 4 x DDR2 SDRAM DIMM (up to 16 GB of DDR2-533/667/800; supporting dual-channel mode when both channel slots are filled symmetrically) there is a list of certified modules
- 3 x PCIEx16 for graphics cards: 2 of them (blue) are compatible with PCI-E 2.0, the third slot is compatible only with the first version of the specs; all three slots always operate in the x16 mode, they can be used in SLI modes, including Triple-SLI (3-way SLI)
- 1 x PCIEx1
- 2 x PCI
- Power connectors: standard ATX 2.2 (24 pins, you can use a regular 20-pin connector, but in this case it's not recommended to use top graphics cards without on-board power connectors, or you should use the 4-pin connector), 8-pin EPS12V for a processor (you can use a standard 4-pin ATX12V connector even without an adapter), and a 4-pin peripheral connector to supply additional power to PCIEx16 slots
- 1 x FDD
- 1 x chipset-based IDE (Parallel ATA) for two ATA133 devices
- 6 x chipset-based SATA-II connectors for six SATA300 devices; connected drives can form RAID 0, 1, 0+1, and 5
- Two connectors for brackets with 4 additional USB ports
- Two connectors for brackets with 2 additional FireWire ports
- 1 x CD/DVD audio connector
- Connectors for analog audio ins and outs on the front panel
- Connector for a bracket with S/PDIF-Out
- Connector for a bracket with S/PDIF-In
- Connector for a bracket with LPT port
- Connector for a chassis intrusion sensor
- Four fan headers (three headers with rpm control), two of them have four pins and allow automatic speed control.




Integrated Controllers

- Audio, based on a 10-channel (7.1+2) Realtek ALC889A HDA codec (it's a top codec from the company that supports full-quality audio output from HD DVD and Blu-ray), 7.1 channel audio, a connector for front line-in/out, S/PDIF-Out jacks (coaxial and optical), S/PDIF-In, and support for some unique functions

- Two network controllers based on the chipset (and Realtek RTL8211B PHY controllers) supporting 10/100/1000 Mbit/s rates (Gigabit Ethernet) and a number of proprietary technologies of NVIDIA, including a hardware firewall (read the details in the chipset review)

- SATA-II RAID based on JMicron JMB363 (marked "Gigabyte", PCIEx1), supporting two SATA300 devices, and RAID 0 and 1 (only a part of this controller's functionality is used)

- FireWire, based on the Texas Instruments TSB43AB23 chip, supporting 3 ports.


The audio codec offers a high signal/noise ratio for sound recording and playback. It can also transfer an audio signal of full quality from DVD Audio, HD DVD and Blu-ray discs to output to HDMI. This function is possible owing to DRM support, so that certified software players can transmit an audio stream without losses to a graphics card (or any other expansion card) with an HDMI port. Besides, the ALC889A supports the DTS Connect technology to connect a computer to a multichannel audio system to obtain the surround sound effect. DTS Neo:PC is also supported. This technology splits a usual stereo signal into 4-8 channels for a surround sound effect with an analog connection to a multi-channel audio system.


Bottom line


You might have noticed that our today's review is too much on the "preliminary side". We have no doubts that a good motherboard on the latest chipset from NVIDIA, the first to offer the real x16+x16+x16 support for the Triple-SLI, will find its share of users. It's hard to say at the moment, whether it will be the Gigabyte 780SLI-DS5 in its current state, an updated Gigabyte 780SLI-DS5, or a different motherboard. As of the negative side, we can mention the necessity to provide better cooling. Perhaps you will have to ignore Gigabyte's attempts to create a passive cooling system for the chipset. Anyhow, the motherboard was unstable in our open testbed, until the only source of active cooling (CPU cooler) was switched from Smart Fan to the full speed mode.

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