AMD'S LATEST ATHLON 64 processors use a new socket and DDR2 memory, essentially requiring a motherboard upgrade. It just wouldn't do to plug a cutting-edge processor into a motherboard with an older chipset, though. Perhaps that's why ATI and NVIDIA are rolling out new core logic to accompany AMD's Socket AM2. In the green corner, NVIDIA is launching a top-to-bottom line of nForce 500 series chipsets, including the high-end nForce 590 SLI. ATI, on the other hand, is finally taking the wraps off its long-awaited SB600 south bridge. That chip is paired with the established CrossFire Xpress 3200 north bridge for high-end multi-GPU platforms.

In many ways, the latest core logic offerings from ATI and NVIDIA are evolutionary designs that address problems with previous chipsets. ATI claims its SB600 resolves the I/O performance problems that plagued the SB450, and NVIDIA promises the nForce 500 series' Gigabit Ethernet acceleration sheds the hardware bug that afflicted the nForce4's ActiveArmor. New features are also on the menu. The SB600 is ATI's first stab at Serial ATA with 300 MB/s and Native Command Queuing, and the nForce 500 series is virtually bursting at the seams with fancy feature names, including FirstPacket, LinkBoost, and DualNet.

Is the combination of ATI's CrossFire Xpress 3200 and SB600 potent enough to prevent NVIDIA's nForce 590 SLI from inheriting the Athlon 64 core logic crown? We've subjected both chipsets to an exhaustive array of application, peripheral, and power consumption tests to find out, and the answer might surprise you.