As its name implies, EVGA nForce 790i Ultra SLI motherboard is based on the latest high-end chipset from nVidia for the Intel platform. What is new on nForce 790i compared to its predecessor, 780i, is the support for DDR3 memories and PCI Express 2.0 support generated by the chipset itself – nForce 780i was in fact an nForce 680i with an additional nForce 200 bridge chip making the conversion between PCI Express 1.0 and PCI Express 2.0. Both chipsets support 3-way SLI mode, which allows three GeForce 8800 GTX’s or three GeForce 8800 Ultras to be connected together, and Quad SLI, allowing two GeForce 9800 GX2’s to be connected together and enjoining four GPU’s, as each GX2 is powered by two GPUs. Two of its three PCI Express x16 slots are PCI Express 2.0 and this motherboard has also two Firewire ports, optical SPDIF output and more.

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Figure 1: EVGA nForce 790i Ultra SLI motherboard.

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 (PCI Express 2.0 video cards available include GeForce 8800 GT, GeForce 9600 GT, GeForce 9800 GX2 and cards from Radeon HD 3400, 3600 and 3800 families).

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. This motherboard also allows Quad SLI, which is a system using two GeForce 9800 GX2’s in parallel (each one contains two video processors). For more information on SLI please read our tutorial on this subject.

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

As you can see on Figure 2, this motherboard also has two PCI Express x1 slots and two traditional PCI slots.

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.

Other basic features from nForce 790i include support for the latest 1,600 MHz external bus (nForce 780i supports only up to 1,333 MHz) and DDR3 memories (up to 8 GB) up to DDR3-1333 or up to DDR3-2000 if EPP (Enhanced Performance Profile, a.k.a. SLI-ready) memories are used. This motherboard doesn’t accept DDR2 memories.

On this motherboard DDR3 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 790i Ultra SLI has a total of eight SATA-300 ports. Six of them are controlled by the south bridge chip, supporting RAID 0, 1, 0+1, 5 and JBOD. The other two ports are controlled by a Jmicron JMB362 chip, and one of them is an eSATA-300 port, soldered on the rear panel of the board. So from the eight SATA ports, seven are SATA-300 and one is eSATA-300. This is great as one of the criticisms we had on the EVGA nForce 780i was the absence of an eSATA port.

This motherboard has two Gigabit Ethernet ports, controlled by the south bridge using two small chips to make the physical layer interface. Unfortunately we couldn’t find out who the manufacturer of these chips is.

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 and one coaxial SPDIF output soldered directly on the motherboard, which is great as you can easily connect it to your home theater receiver. This is a better configuration than the one provided by the EVGA nForce 780i motherboard, which didn’t provide a coax connector, only optical.

This motherboard has ten USB 2.0 ports, six soldered on the rear panel and four available thru 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 thru an I/O bracket that also comes with the board (both connectors use the standard Firewire connector, not the mini one).

On Figure 3 you can see the motherboard rear panel: PS/2 keyboard connector, PS/2 mouse connector, coaxial SPDIF out, optical SPDIF out, eSATA-300 port, Firewire port, six USB 2.0 ports, complete set of analog 7.1 audio jacks and two Gigabit Ethernet ports.

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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 thru an I/O bracket that comes with the product.