Although ATi's Crossfire multi-GPU rendering technology has become a reasonable alternative to SLI, the Radeon Xpress 200 CrossFire Edition chipset is still saddled with a comparatively poor south bridge chip. ATI's SB450 is missing a number of handy features, such as support for Native Command Queuing and RAID 0+1 and 5 arrays. More importantly, though, it's plagued by I/O issues that hinder USB and PCI performance. That latter is particularly damning, as it can affect the performance of onboard Firewire, Gigabit Ethernet, and Serial ATA peripherals.

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