X-bit labs

VIA PT880 Preview: Soltek SL-86SPV2-RL Mainboard in Our Lab (page 2)

Category: Chipsets

by Ilya Gavrichenkov

[ 09/09/2003 | 12:14 PM ]

VIA PT880 in Detail

First, let’s talk about the chipset, and then go over to the mainboard. VIA PT880 is following in the wake of VIA’s single-channel PT800, which proved to be a successful product. In its turn, VIA PT880 is going to be followed by other dual-channel chipsets. The company is planning to introduce an analogous dual-channel chipset for Socket A processors, VIA KT880. VIA’s roadmap lists some other Pentium 4 products to come, particularly with support of DDR-II memory and PCI Express bus.

The architecture of VIA PT880 follows classic examples, but introduces some distinguishing features.

The main characteristics of this chipset include:

• Support of Intel Pentium 4/Celeron processors with 400/533/800MHz FSB and Hyper-Threading technology;
• Two 64-bit memory channels with support of DDR266/DDR333/DDR400 SDRAM and QBM533 SDRAM;
• AGP 8x/4x support;
• Ultra V-Link bus connecting the North and South Bridges of the chipset;
• VIA VT8237 South Bridge.

First, let’s say a few words about the memory controller employed in VIA PT880. The chip really deserves it. Unlike the controller in i865, it supports ECC, thus allowing the chipset to handle tasks that require high reliability and security of data. Secondly, VIA PT880 is the first chipset to support Quad Band Memory (QBM) from Kentron.

In a nutshell, QBM technology is such:

1. One QBM SDRAM module actually accommodates two ordinary DDR SDRAM devices (banks);
2. The clock signal of the second DDR SDRAM bank is shifted by 90 degrees in relation to the first;
3. The QBM10 switch unit integrated into each QBM SDRAM module provides access to the both banks along the same bus;

   

4. As a result, this memory supports transfer of 4 bit per clock cycle compared to 2 bit with ordinary DDR SDRAM.