HD Tach
We used HD Tach 3.01's 8MB zone test to measure basic SATA throughput and latency.

The 780i SLI's transfer rates look a little low here. Write speeds are higher than they should be for all the chipsets, though. The combination of HD Tach's write speed test, our Raptor hard drive, and chipsets that implement Native Command Queuing tends to produce artificially inflated scores.

Access times are pretty close, although the 780i SLI is half a millisecond off the 680i.

CPU utilization results are close considering HD Tach's +/- 2% margin of error in this test.

USB performance
Our USB transfer speed tests were conducted with a USB 2.0/Firewire external hard drive enclosure connected to a 7200RPM Seagate Barracuda 7200.7 hard drive. We tested with HD Tach 3.01's 8MB zone setting.

Recent Nvidia chipsets have had a knack for USB, and that trend continues with the 780i SLI. The chipset not only delivers the fastest burst speeds of the lot, but its write speeds are a couple of MB/s quicker than Intel's fastest chipset. CPU utilization is nice and low, as well.