At this year’s end, NVIDIA announces the release of its nForce 700i series chipsets, the 780i and 750i. The main innovation is actually in terms of 2.0 PCI Express support.
This support is a bit particular however because it is done via the addition of a third chip, the nForce 200, besides the SPP (northbridge) and MCP (southbridge). Connected in PCI-Express to the SPP, it enables the management of 32 PCI-Express 2.0 lanes which can be attributed to 2 or 4 graphic ports. In total the bandwidth available between the nForce 200 and graphic cards is 16 GB /s while this is only 7.2 GB /s between the nForce 200 and SPP as this interface is via 16 PCI-Express 1.0 lanes which have been boosted by 80% compared to their normal speed.
This doubling of PCI Express lanes on the SPP level allows NVIDIA to offer a triple SLI solution using 3 ports cabled in x16 on the nForce 780i, one being relayed to the SPP. On the 680i the third port was in x8. We will just have to wait and see if this adds any advantage for tri-way SLI.
Note that while NVIDIA had to rely on a new chip for PCI Express, this is because the SPP and MCP do not really differ from those used on the nForce 680/650i. While Yorkfield (45nm Core 2 Quad) compatibility is now possible due to a modification on motherboards (which delayed their release a month) we are officially limited to an FSB1333 at the moment. This is when Intel will release a QX9770 using an FSB1600 in January. In terms of memory, there is still DDR2 up until DDR2-1200 while again Intel offers DDR3 on the X38, though this is really only of very limited interest at the moment.
The southbridge is the same and therefore has two Gigabit Ethernet ports, which can be combined with DualNet technology, and 4 to 6 SATA ports depending on the version that can be configured in RAID 0, 1, 0+1 and 5. For overclocking, besides management of the Penryn half multiplier, NVIDIA proposes precise control of GTLVRE voltage in its NVBios integrated to motherboards using the reference design. NVIDIA points out having attained a maximum FSB of 465 MHz with a Yorkfield.
The fact that this appears more like an nForce 690i rather than an nForce 780i will allow them to respond (EVGA, XFX and ASUS motherboards are planned for the end of the month) to immediate demands for a Yorkfield compatible platform and will also enable the use of SLI and even Tri-way SLI. Nevertheless, one year after the 680i, we are awaiting a truly new chipset with native support of PCI Express 2.0 for the SPP and FSB1600 or even DDR3 management. In fact, this is on the way from NVIDIA and is called the nForce 790i arriving at the beginning of 2008. It therefore seems important to wait a bit.
