Serial ATA performance
The Serial ATA disk controller is one of the most important components of a modern core logic chipset, so we threw each platform a selection of I/O-intensive storage tests using a Western Digital VelociRaptor. The 780G and 790GX are at a disadvantage here because we're running them in native IDE mode, which doesn't support Native Command Queuing. AMD's south bridge chips must be run in AHCI mode to enable command queuing, but performance problems associated with that mode in both the company's SB600, SB700, and SB750 south bridge chips remain a thorn in the side of both the 780G and the 790GX.

IOMeter
We'll begin our storage tests with IOMeter, which subjects our systems to increasing multi-user loads. Testing was restricted to IOMeter's workstation and database test patterns, since those are more appropriate for desktop systems than the file or web server test patterns.

An AHCI mode that actually works pays big dividends for the GeForce 9300, which easily outruns the AMD chipsets in IOMeter. The 9300 essentially ties the GeForce 8300 and G45 Express here.

Response times cast a different light on IOMeter performance, and again, the GeForce 9300 is much snappier than either AMD chipset.

Of all the chipsets running in AHCI mode (and thus delivering significantly better IOMeter performance), the GeForce 9300's CPU utilization is the lowest. Only a couple of percentage points separate the 9300 from the G45, though.