nForce 600 (cont’d)

Like the nForce 5 line, NVIDIA offers multiple tiers for the nForce 6 family. At the top of the nForce 6 food chain is the aforementioned nForce 680i. This is the chipset for hardware enthusiasts and gamers who crave the most performance and headroom for overclocking.

Enthusiast-level performance comes at a price however, and thus nForce 680i motherboards sell for north of $200 online. For end users looking to spend a little less NVIDIA provides two additional options, the nForce 650i SLI chipset and nForce 650i Ultra.

nForce 650i SLI/Ultra

Like the nForce 680i SLI, the 650i is a dual-chip configuration. However, it is radically different after that. Gone are the dual x16 PCI Express Graphics (PEG) slots. Instead the nForce 650i chipset splits the PCI Express lanes in SLI mode: eight go to the primary PEG slot, and the remaining eight lanes go to the secondary slot.

When using one GPU, the nForce 650i chipset sends all sixteen lanes to the primary PEG slot.

Another difference between nForce 650i and nForce 680i is memory support. Whereas nForce 680i SLI supports up to 1200MHz SLI Memory with EPP, the nForce 650i SLI chipset only supports DDR2 speeds up to 800MHz. Anything beyond that is officially considered overclocking and isn’t guaranteed. In addition, FSB speeds up to 1066MHz are all that’s supported, unlike nForce 680i SLI the 650 chipset doesn’t explicitly support 1333MHz FSB operation, and the chipset hasn’t been validated for “extreme FSB overclocking”. In other words, the nForce 650i chipset hasn’t been designed with overclocking in mind like the nForce 680i SLI is. Your overclocking mileage may vary.

The South Bridge on the nForce 650i SLI isn’t as robust as nForce 680i either. The chipset supports up to 8 USB ports and the storage controller supports more parallel ATA drives (4) but gives up two SATA ports (up to four SATA drives are supported). Considering the target market of this chipset is more likely to have older parallel hard drives, this 4x4 configuration makes sense in our opinion, although it is a shame to lose 2 SATA ports. The chipset also lacks support for NVIDIA networking features such as teaming and TCP/IP acceleration, which allows users to combine both GigE connections for better performance as well as packet prioritization.

For single GPU users, NVIDIA also offers the nForce 650i Ultra chipset. It shares most of the key features found in the nForce 650i SLI, with the obvious omission of dual x16 graphics slots for SLI.

The following chart summarizes the differences between NVIDIA’s latest chipsets:

nForce 600 lineup
	nForce 680i SLI	nForce 650i SLI	nForce 650i Ultra
FSB (MHz)	1333	1066	1066
Extreme FSB Overclocking	Best	Good	Good
NVIDIA SLI Technology	Yes 2x16	Yes 1x16/2x8 in SLI	No
NVIDIA LinkBoost Technology	Yes	No	No
Third PEG Slot	Yes	No	No
SLI-Ready Memory with EPP	1200MHz	800MHz	800MHz
JEDEC DDR2 Memory	800MHz	800MHz	800MHz
PCI Express # of Lanes	46 lanes	18 lanes	18 lanes
PCI Express # of Links	9 links	4 links	3 links
Configuration	16, 16, 8, 1, 1, 1, 1, 1, 1	8, 8, 1, 1 or 16, 1, 1	16, 1, 1
SATA/PATA Drives	6/2	4/4	4/4
SATA Speed	3Gb/s	3Gb/s	3Gb/s
RAID	0, 1, 0+1, 5	0, 1, 0+1, 5	0, 1, 0+1, 5
NVIDIA MediaShield	Yes	Yes	Yes
Native Gigabit Ethernet Connections	2	1	1
NVIDIA FirstPacket Technology	Yes	Yes	Yes
NVIDIA DualNet Technology	Yes	No	No
Teaming	Yes	No	No
TCP/IP Acceleration	Yes	No	No
NVIDIA nTune Utility	Yes	Yes	Yes
USB Ports	10	8	8
PCI Slots	5	5	5
Audio	Azalia HD Audio	Azalia HD Audio	Azalia HD Audio