EVGA nForce 780i SLI Motherboard
By Gabriel Torres on December 19, 2007


Introduction

As its name implies, EVGA nForce 780i SLI motherboard is based on the latest high-end chipset from NVIDIA for the Intel platform. What is new on nForce 780i is its support for the new 3-way SLI mode, which allows three GeForce 8800 GTX’s or three GeForce 8800 Ultras to be connected together. Two of its three PCI Express x16 slots are PCI Express 2.0 and this motherboard also has two FireWire ports, optical SPDIF output and more.

Even though this motherboard is being marketed by EVGA it is in fact manufactured by NVIDIA (“Designed by NVIDIA” program which was introduced with nForce 680i chipset), so this board is identical to the nForce 780i motherboard from XFX. Other motherboard manufacturers like ASUS, MSI, Gigabyte and ECS haven’t released nForce 780i products yet, so we can’t comment if they are going to just resell this motherboard manufactured by NVIDIA or if they will design their own products.

By the way, technically NVIDIA also does not manufacture this motherboard. Since NVIDIA doesn’t have factories, they design the board and hire another manufacturer to actually produce it.

nForce 780i
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Figure 1: EVGA nForce 780i SLI motherboard.

nForce 780i is in fact a propelled version of 680i: they both use the same north bridge chip. The only difference between the two is that 780i uses a small nForce 200 bridge chip to allow PCI Express 2.0. The communication between nForce 780i and nForce 200 is done through an overclocked PCI Express 1.0 path. Then nForce 200 makes the connection with the three x16 PCI Express slots available. Two of them are 2.0 and one of them is 1.0. All three slots work at x16 rate when SLI mode is enabled, which is great.

If you pay close attention you will see that the layout of the motherboards “designed by NVIDIA” based on these two chipsets is identical (click here to see nForce 680i “designed by NVIDIA” motherboard).

Native support for PCI Express 2.0 will only be available on the next high-end NVIDIA chipset for the Intel platform, namely nForce 790i, which will compete with Intel X38, as it will also bring DDR3 support.

PCI Express 2.0 doubles the bandwidth available for video cards from 2.5 GB/s to 5 GB/s, if they are also based on PCI Express 2.0 (so far the only PCI Express 2.0 video cards available are GeForce 8800 GT, Radeon HD 3850 and Radeon HD 3870).

PCI Express 2.0 x16 slots are physically identical to PCI Express 1.0 x16 slots, so you can install PCI Express 1.0 cards without any problem. As we mentioned, this motherboard supports the new three-way SLI mode, which allows you to install three GeForce 8800 GTX’s or three GeForce 8800 Ultras in parallel. Other video cards don’t support three-way SLI. Of course you still can use the traditional SLI mode with two video cards. For more information on SLI please read our recent tutorial on this subject.

nForce 780i
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Figure 2: Three PCI Express x16 slots (two 2.0 and one 1.0) supporting three-way SLI.

This motherboard also supports ESA (Enthusiast System Architecture), the new interface for monitoring and controlling devices such as coolers, cases and power supplies. In fact ESA isn’t hardware-dependent as it uses the USB bus, but you need software to control and monitor ESA devices and so far the only program that can read the status of any ESA component independently of its brand is the one from NVIDIA, that runs on this motherboard. For more information on this technology read our ESA Explained tutorial.

Since nForce 780i uses the same chips as nForce 680i all other features from 780i are identical to 680i: support for the 1,333 MHz external bus, support for DDR2 memories (up to 8 GB) up to DDR2-800 or up to DDR2-1200 if EPP (Enhanced Performance Profile) memories are used, etc.

On this motherboard DDR2 sockets 1 and 3 are gray and 2 and 4 are black. In order to enable dual channel feature, which doubles the maximum theoretical transfer rate from the memory system, you need to install two memory modules on sockets with the same color (or four modules, which will use all available sockets).

EVGA nForce 780i has six SATA-300 ports controlled by the south bridge chip, supporting RAID 0, 1, 0+1, 5 and JBOD. We think that for a truly high-end motherboard the only thing missing on this board is eSATA ports.

This motherboard has two Gigabit Ethernet ports, controlled by the south bridge using two Marvell 88E1116 chips to make the physical layer interface.

The audio section from this motherboard provides 7.1 audio, produced by the south bridge chip with the aid of a Realtek ALC888 codec, which provides a 90 dB signal-to-noise ratio for its inputs and a 97 dB SNR for its outputs and a maximum sampling rate of 96 kHz for its inputs and 192 kHz for its outputs. For a high-end motherboard we expected a better codec to be used. Even though these specs are o.k. for the average user we think this board should have at least 100 dB SNR for its outputs and at least 95 dB SNR for its inputs and also 192 kHz sampling rate on its inputs. This basically means that if you are willing to work professionally capturing and editing analog audio (e.g., converting LPs to CDs or MP3, converting VHS to DVDs or any other digital format, etc) you will need an add-on sound card for better audio quality, as the on-board audio will produce too much white noise (i.e., background noise).

This board has one optical SPDIF output soldered directly on the motherboard, which is great as you can easily connect it to your home theater receiver. It doesn’t come with an on-board coaxial SPDIF connector but it has a header for installing one (the board doesn’t come with this bracket, however).

This motherboard has ten USB 2.0 ports, six soldered on the rear panel and four available through I/O brackets, which come with the motherboard, and two FireWire (IEEE1394) ports controlled by a Texas Instruments TSB43AB22A chip, one soldered on the rear panel and one available through an I/O bracket that also comes with the board.

In Figure 3, you can see the motherboard rear panel with PS/2 keyboard connector, PS/2 mouse connector, FireWire port, six USB 2.0 ports, optical digital audio (SPDIF) outputs, complete set of analog 7.1 audio jacks and two Gigabit Ethernet ports.

nForce 780i
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Figure 3: Motherboard rear panel.

As you can see, this motherboard doesn’t have parallel and serial ports, although one serial port is available through an I/O bracket that comes with the product.

More Features

EVGA nForce 780i comes with other smaller features, like on-board reset and power switches, which are quite convenient for overclockers.

nForce 780i
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Figure 4: Buzzer and reset and power switches.

This motherboard also has a POST (Power On Self Test) diagnostics display. This feature allows you to know through a series of two-digit codes what is wrong if your computer doesn’t turn on.

nForce 780i
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Figure 5: POST display.

This motherboard uses solid aluminum capacitors on the voltage regulator circuit, as you can see in Figure 6. This is great because it prevents the infamous capacitor leakage problem. The other electrolytic capacitors used on this motherboard, however, are regular ones, manufactured by Samxon, which is a Chinese company (Japanese capacitors are better). This motherboard also uses iron chokes on the voltage regulator circuit, while tier 1 manufacturers like Gigabyte and ASUS are using ferrite chokes on their high-end products, which offer a lower power loss.

nForce 780i
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Figure 6: Voltage regulator circuit.

In Figure 7, you can see all cables and accessories that come with this motherboard, which include both SLI and three-way SLI bridges.

nForce 780i
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Figure 7: Motherboard accessories.

Main Specifications

EVGA nForce 780i SLI main features are:

* Researched at Pricewatch.com on the day we published this First Look article.

Conclusions

This motherboard is clearly targeted to the high-end gamer that is looking for PCI Express 2.0 slots and thinking about three-way SLI for the ultimate gaming machine.

At first we thought that the new AMD Spider platform with its CrossFireX – which allows not three video cards in parallel, but four – could be a serious competition to nForce 780i, but the problem is that CrossFireX isn’t operational yet, as AMD hasn’t released drivers to allow this configuration yet. The word is that this will happen only in February 2008. So if you want to build the ultimate gaming machine today, nForce 780i and three-way SLI is the way to go.

Keep in mind that three-way SLI only works with three GeForce 8800 GTX’s or three GeForce 8800 Ultras.

The main problem with this motherboard is its low cost/benefit ratio – it is just too expensive, costing USD 290 in the USA. We think that for a high-end motherboard at this outrageous price label this motherboard should use a better audio codec, all capacitors should be solid and not only the ones from the voltage regulator circuit, use ferrite chokes, have on-board coaxial SPDIF connector and have at least one eSATA port. On the other hand this motherboard provides a POST diagnostics display, which is great.

Originally at http://www.hardwaresecrets.com/article/EVGA-nForce-780i-SLI-Motherboard/508


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