VIA Apollo KT266A Chipset Review
A New Chipset North Bridge
This content was originally featured on Amdmb.com and has been converted to PC Perspective's website. Some color changes and flaws may appear.The KT266A chipset consists of the brand new 552-pin VT8366A DDR North Bridge and the already well known 376-pin VT8233/C V-Link South Bridge. So, what improvements have VIA made to the North Bridge that have gotten reviewers such as myself so excited about it?
In truth, there is nothing very revolutionary about the changes that were made in this new revision of the chipset. The latest changes are titled by VIA as the Enhanced Memory Controller With Performance Driven Design. The new features and technology include tightened timings on the S2K front side bus, deeper instruction and data queuing, and the ability to burst up to eight Quad Words per clock cycle. The timings that are improved result in a faster transfer rate between the synchronized Front Side Bus and Memory Bus. The eight Quad Words per clock is up from four in the previous chipset designs. The data queues were also deepened, allowing faster and more efficient access to the buffered data.
The image below is a graph of the setup of the new KT266A chipset. It is very similar to the previous KT266 with the exception of the Performance Driven Design section on the North Bridge.
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While not new or unique to the KT266A chipset, the VT8366A North Bridge has full support for both the DDR200 and DDR266 (PC1600 and PC2100, respectively) as well as PC100 and PC133 memory. This means that the manufacturers have the option of including both/either SDRAM and DDR DRAM options. Hopefully this will result in some lower cost motherboards that still have the advantages of the new KT266A chipset.
Many may not be aware, but VIA chipsets support a technology they call the V-Link, where the North Bridge and South Bridge communicate on a dedicated 266 MHz bus. Other chipsets use the PCI bus, causing slow interfacing between the two chipsets and perhaps even slow down on the PCI bus itself. The North Bridge still supports both AGP 4x and 2x cards and also gives the manufacturer the option of including an AGP Pro slot.