Chipset features compared
Before we dive into the benchmarks, let's recap the differences between the KT400A, its immediate predecessor, and its toughest competitor.

NVIDIA nForce2 VIA KT400 VIA KT400A
Memory types
(DDR only listed)		 PC1600 PC2100 PC2700 PC3200 DDR SDRAM PC1600 PC2100 PC2700 PC3200 DDR SDRAM PC1600 PC2100 PC2700 PC3200 DDR SDRAM
Max. effective memory clock speed 400MHz 333MHz
(400MHz unofficial)		 400MHz
Memory bus width 2 * 64 bits 64 bits 64 bits
Peak theoretical memory bandwidth 6.4GB/s 2.7GB/s
(3.2GB/s)		 3.2GB/s
Maximum addressable RAM 3GB 4GB 4GB
Max. AGP mode 8X 8X 8X
North/south bridge interconnect HyperTransport V-Link V-Link
Interconnect clock speed 400MHz 533MHz 533MHz
Interconnect bus width 2 * 8 bits 8 bits 8 bits
Peak theoretical interconnect bandwidth 800MB/s 533MB/s 533MB/s
Disk interface support up to... ATA/133 ATA/133 ATA/133
USB mode support 2.0 2.0 2.0
USB controllers/ports 3/6 3/6 3/6
IEEE 1394 controller Y N N
AC97 audio channels 6 6 6
Network interfaces Dual 10/100Mbps Ethernet 10/100Mbps Ethernet 10/100Mbps Ethernet

As you can see, it's a very close contest in terms of features. The nForce2 has more memory bandwidth, of course, and we'll see whether that matters shortly. Otherwise, the differences are small. NVIDIA's chipset has IEEE1394 support, which, surprisingly, the KT400A lacks. The VIA chipsets, however, can address up to 4GB of memory, while the nForce2 tops out a gig lower.

To give you a better sense of how all of these things fit together inside a PC, have a look at the block diagram of the KT400A below. You can see how duties are split between north and south bridge chips, and you can see that I've fulfilled my duty as a guy writing a chipset review to provide a fuzzy block diagram of said chipset.


Source: VIA