Speaking of the success of the 694X chipset, there is actually a contribution from Intel. Intel made some mistakes. The i820 chipset used too many advanced technologies and left many bugs.
VIA has gradually added new innovations. First, it introduced VIA Apollo Pro 133 chipset, and supported 133M external frequency for the first time. After the market matured, VIA Apollo Pro 133A(694X chipset) supporting APG 4x was introduced.
The design of VIA Apollo Pro 133A is basically similar to its predecessor Apollo Pro 133. The biggest difference is the addition of AGP 4x. VIA Apollo Pro 133A adopts 133MHz memory and system frequency, which can support asynchronous operation of memory, that is, the frequency of memory and system can be set independently.
VIA Apollo Pro 133A chipset is composed of North Bridge chip VT82C694X (which is why it is called 694X chipset) and South Bridge chip VT82C596B (or VT82C686A) connected by PCI bridge. VIA doesn't adopt the HUB architecture adopted by Intel now, and VIA engineers still think that the bandwidth of PCI bus is enough for the bridge connecting chips to ensure the normal work of chipset. Apollo Pro 133A chip adopts 0.35 micron and three-layer metal wiring technology, which generates little heat.
Apollo Pro 133A has very attractive performance parameters, four USB interfaces, allowing more connections and perfect hardware support. Of course, the most attractive thing is its AGP 4x and PC 133 SDRAM.
VIA Apollo Pro 133A supports the brand-new hard disk transmission interface Ultra DMA/66, and VIA Apollo Pro 133A fully supports AC'97 specification, so the function of soft sound card can be realized by using the built-in encoder. Of course, using AC'97 specification will reduce the performance of the system.
Another important feature is that VIA Apollo Pro 133A supports VCM memory produced by NEC, which reduces the delay caused by SDRAM precharge.