Closer Look at Nvidia nForce 790i SLI

But before we start talking about ASUS Striker II Extreme, we should say a few words about Nvidia nForce 790i SLI chipset. It is a really new solution, and not a slightly modified previous-generation chipset like nForce 780i SLI and nForce 750i SLI. The new chipset we are talking about today consists of two and not three bridges, since PCI Express 2.0 is now finally supported in the SPP North Bridge (System Platform Processor) and not implemented by an additional controller. Moreover, nForce 790i SLI supports faster DDR3 SDRAM and officially supports processors with 1600MHz bus.

As a result, the block diagram for the new Nvidia nForce 790i SLI looks as follows:

We can see right away that all the innovations of the new nForce 790i SLI have been made in the North Bridge. As for the South Bridge, Nvidia engineers believe it is still up-to-date that’s why they have been leaving it as is for years already. It is partially true, however, some people may get very concerned that the new nForce 790i SLI uses an MCP (Media and Communications Processor) developed two years ago for nForce 570a SLI.

nForce 790i SLI uses an absolutely new SPP (North Bridge). It is responsible for two PCI Express x16 2.0 graphics card slots. Additional PCI Express x16, x8 and x1 slots are implemented via the chipset South Bridge and do not support version 2.0 of the protocol. That is why nForce 790i SLI is first of all designed to support dual-card SLI configurations. In fact, Nvidia stresses that the third PCI Express x16 slot is intended for a physics accelerator. So, Nvidia gives everyone to understand very clearly that experiments with three- or four-card SLI configurations are very unlikely to become a mass solution any time soon.

Speaking of the SLI, we can’t help mentioning that nForce 790i SLI is the last Nvidia chipset without the integrated graphics core. Even nForce 790a SLI for Socket AM2+ platform launched just a little after already features an integrated graphics core. It is primarily introduced for Hybrid SLI and Hybrid Power technologies, which disable the external graphics in 2D mode where GPU performance is of minimal importance.

Besides the fresh PCI Express bus controller, the new chipset North Bridge also acquired an updated memory controller supporting DDR3 SDRAM. I have to point out that unlike integrated memory controllers from Intel, Nvidia solution is not backward compatible with DDR2 SDRAM. Therefore, Nvidia nForce 790i SLI based mainboards features only DDR3 DIMM slots. Overall, this is a good time to switch to new memory standard. Although a lot of users still consider DDR3 SDRAM to be expensive and unnecessary exotics, Intel has done a great job in preparing the market for it. Moreover, DDR3 SDRAM can work synchronously with the processor FSB, thus ensuring better performance in Nvidia chipsets due to lower latencies.

Transition to DDR3 SDRAM required Nvidia to develop new EPP spec – Enhanced Performance Profiles 2.0. This specification provides SPD expansion for saving settings profiles during overclocking this time for DDR3 SDRAM. And although EPP 2.0 technology is a complete analogue of Intel’s XMP, the profiles supported by different companies’ chipsets are not compatible.

Note that Nvidia offers two identical versions of its new chipset: nForce 790i SLI and nForce 790i Ultra SLI. Besides the price for the mainboard makers, these chipsets have only one difference: a more expensive modification is formally compatible with up to DDR3-1000 overclocker memory modules. In reality it means that nForce 790i Ultra SLI is simpler to configure with high-speed DDR3 SDRAM EPP 2.0 memory modules: all necessary parameters can be set automatically. In manual configuration mode both nForce 790i SLI modifications have no limitations for memory bus clock speed. That is why nForce 790i Ultra SLI as well as nForce 790i SLI have almost the same chances to end up in an enthusiast’s computer.

As for the alternative solutions from other manufacturers, the closest rival to the new Nvidia chipsets in both: price and features will be Intel X48 Express. However, it is important to understand that it is not direct competition, since X48 Express doesn’t support SLI configurations, which remains nForce’s exclusive feature. Nevertheless, graphics subsystems made of several GeForce graphics cards are not that widely spread these days, so it makes some sense to still compare the functionality of the new nForce 790i SLI against Intel X48 Express:

As we see, top Nvidia and Intel chipsets have very similar base specifications. However, nForce 790i SLI looks more attractive from several standpoints: number of supported PCI Express lanes as well as bus bandwidth between the chipset North and South Bridges. Also, Nvidia chipset with two Ethernet controllers offers between networking functionality due to Teaming support. Besides, it also supports Parallel ATA interface that has been long gone from Intel South Bridges. In fact, the only thing Intel X48 Express is superior in, is the number of USB ports.

However, do not take this specification comparison too seriously. Mainboard manufacturers can easily add the missing functionality with additional controllers when designing their products. Moreover, it is not the official claimed specifications that are important, but the way they actually work.

That is why let’s get to know the new mainboard based on Nvidia nForce 790i SLI chipset.