NForce 680i LT & support for 45nm Q9550 - gimme some input/feedback

I'm surprised yours booted at all? The 680i does lack support for the 45nm quads. Do you have any data on the lockups? (error msgs, blue screen numbers, etc)

Does the LT designation mean something? Some second gen 680i that I didn't hear about?

Here are the fundamental differences between an nForce 680i SLI board and an nForce 680i SLI LT board.

No Triple PCIe x16 Card Support - Full nForce 680i platforms support dual PCI Express x16 cards along with a third PCI Express x16 slot (with x8 signaling). This slot is designed for dedicated PCI Express physics cards (which have still yet to hit the market) or an additional graphics card or RAID card. As utilization of this slot has been low, Nvidia decided to cut out this feature in order to cut down on costs. Most users will not miss this slot.

No Dual-LAN Support - The nForce 680i LT SLI chipset only supports one native Gigabit Ethernet port, as opposed to two on the 680i SLI. This also means that Nvidia's DualNet technology (which pairs multiple GigE links together) is out of the running on this chipset. The 680i LT SLI only supports a single Gigabit Ethernet port and Nvidia's FirstPacket priority optimization features. We should note that third party motherboard manufacturers could indeed provide dual-NICs, although they would have to rely on third party components connected to the PCIe/PCI bus, not native to the chipset. The majority of users only use one Gigabit Ethernet port, so again, this feature won't be missed by many.

No DDR2-1200 Support - This chipset only "officially" supports memory speeds up to 800 MHz, whereas the full 680i SLI chipset supported speeds up to 1200 MHz officially. Keep in mind, while this chipset only "officially" allows DDR speeds up to 800 MHz, the BIOS of this motherboard is fully equipped to run at much higher speeds, which we verified in testing.

No Board Level "Bling" - eVGA's full 680i SLI board featured a black PCB and diagnostic LED indicators, whereas this 680i board features no LED indicators and a standard green PCB.

Active Cooling - In our opinion, this may be the biggest notable change between the 680i SLI and the 680i LT SLI boards from eVGA. In order to cut down costs, eVGA/Nvidia removed the passive heatpipe based cooling of the two chipset components, opting instead for two small chipset coolers, each with fans. Now, the original 680i SLI's heatpipe cooler ran fairly hot so using the (optional) fan was more or less a requirement for power users. However, this board takes this efficient cooling system out of the mix, going for a more traditional route which is a noisier solution overall.

Then I don't see how this 680i board can boot with the 45nm quad. If you're having problems with stability that could be it. From what I've seen on the forums you shouldn't even be able to boot.

Have you verified the chip with CPUz?

Any P or G 3x or 4x board should handle it, as will the 7 series from Nvidia. (750i, 780i, etc)

How unstable are we talking about?

I'd look for updated drivers. Thats my first thought. I was thinking bad board until you mentioned linux.