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VIA's KT880 chipset


Socket A's not dead yet
— 12:00 AM on April 29, 2004

WAY BACK in November of last year, we declared VIA's KT600 chipset a viable alternative to NVIDIA's well-worn nForce2 chipset. Serial ATA RAID support and superior peripheral performance made the KT600 a more attractive platform than the nForce2 from a features standpoint. However, the KT600's single memory channel was no match for the dual-channel nForce2 in our application benchmarks, where the nForce2 easily won the majority of our tests.

Simply being a viable alternative to the nForce2 wasn't good enough for VIA, it seems. The company has rolled out a new KT880 chipset for Socket A processors, and this one features a dual-channel memory controller. Can the new KT880 snatch the Socket A performance crown from our reigning champion, the nForce2 Ultra 400? Read on to find out.


VIA's KT880 north bridge...


And venerable VT8237 south bridge

The chipset
When compared with the KT600, the KT880's only new feature is its DualStream64 dual-channel memory controller. DualStream64 is more than just an extra 64-bit memory channel, though. The memory controller also features improved branch prediction, an enhanced data prefetch protocol, and other tweaks to improve performance. The KT880 is designed to work with DDR400 and DDR333 memory, and like all dual-channel designs, two DIMMs must be used to achieve optimal performance.

Interestingly enough, the KT880's new memory controller can address up to 8GB of memory. The KT880 north bridge also features an AGP 8X graphics interface and supports a 400MHz front-side bus.


A block diagram of the KT880 chipset. Source: VIA

The KT880 north bridge links into the chipset's VT8237 south bridge with VIA's V-Link interconnect. This particular incarnation of V-Link offers 533MB/sec of bandwidth between the chipset's north and south bridge components, which should be enough for most users.

On the south bridge, the VT8237 sports eight USB 2.0 ports, a six-channel audio controller, 10/100 Fast Ethernet, two ATA/133 channels, and four Serial ATA ports with support for RAID 0, 1 and 0+1 arrays. Although the VT8237 natively supports up to four Serial ATA devices, an external PHY chip is required to access two of the south bridge's four SATA ports. Mobo manufacturers have traditionally shied away from using external PHYs to tap the VT8237's extra two SATA ports, so I wouldn't hold out for a KT880 board with four SATA ports hanging off the south bridge.

Even when only two of its Serial ATA ports are tapped, the KT880 still has a leg up on NVIDIA's current nForce2 chipsets, whose MCP south bridge chips lack any Serial ATA functionality. However, NVIDIA has pledged to bring Serial ATA support, among other features, to the nForce2 chipset with a new MCP, so VIA's Serial ATA advantage may not last.