Articles :: Introduction to Chipsets ::

Billy Newsom · 01-01-1997 · Category: Tech-planations

Non-Intel Pentium Chipsets

Very few people are as familiar as I am with the chipset discussed below. The problem is that the other chipset makers don't sell their products to many well-known motherboard manufacturers and their volume is probably 1/5th of the Intel chipsets.


VIA is probably the world's third-largest chipset maker. They compete with Intel by low prices and by targeting the low-end systems. They could soon become the dominant supplier of Socket 7 motherboard chipsets if their new products catch on. I am particularly impressed with the VIA Apollo VP2/97, the VPX, the VP3, and now the MVP3. These chipsets aren't for low-end systems, since they support more features and have a higher level of integration than Intel's latest chipsets. They are primarily a Taiwanese company on the manufacturing side, with many R&D and tech support engineers in the U.S.

The MVP3, for example, has the following features: 100 MHz memory bus speed (with the proper PCI bus speed), SDRAM, DDR SDRAM, ECC, parity, and EDO RAM support, up to 2048 KB external cache, up to 1 GB of system RAM (512 MB cacheable), ATA-33 support, USB, and ACPI. No doubt this chipset beats the 430TX by a long shot, and is somewhat better than recent ALi and SiS chipsets. It does not support dual processors, but then I never saw a single implementation of SMP on other VIA chipsets that did.

The VP2/97 is a more direct competitor of the 430TX. It supports: SDRAM, BEDO, ECC, parity, and EDO RAM support, up to 2048 KB external cache, up to 512 MB of system RAM, SMP support, ATA-33 support, and ACPI. No doubt this chipset is a 430TX killer. The AMD-640 is the same as the VP2/97. Both chipsets officially claim to be capable of 75 MHz, however it's not the chipsets which usually have the problems at this speed, it's the memory and the PCI cards.

The VIA VPX/97 has many of the features of VP2/97, plus it allows an asynchronous PCI bus. Cyrix devotees will be happy about this, since an asynchronous bus is required for both the 6x86 PR200 and 6x86MX PR2-233, which run at 75 MHz externally. By using an asynchronous bus, the VPX alleviates the problem of the 37.5 MHz PCI bus, which can cause problems under some conditions. I must stress that the VP2 and AMD-640 are synchronous chipsets and running the memory bus at 75 MHz will violate the PCI specification of 33 MHz.

The VP3 was the first chipset to support AGP. It's a lot like the VP2/97 with support for up to 1 GB of memory and AGP. Many recent motherboards were based on this chipset. I saw quite a few of them at Fall Comdex 1997. This time, AGP beat the (1997) Christmas rush, which MMX did not & AMD

Close to VIA Technology is AMD. AMD made two agreements with VIA. Although their press release indicates that AMD has licensed the VP2/97 chipset to make their own, called the AMD-640, the truth is that the AMD-640 is a VIA VP2/97 with AMD labels on it, made at the same TSMC fab. This revelation is a good thing for people looking for one chipset and finding the other & the chipsets are 100% interchangeable. Later, AMD will be using their second agreement with VIA, the one they talk about in the press release. This is a technology license agreement that allows AMD to see all of the secrets of the VP2/97, I mean AMD-640, and then build their own chipsets with that knowledge. As I said, AMD manufactures the AMD-640 at the same TSMC foundry that VIA uses. AMD wants to showcase their chipset as an alternative to Intel's PCIsets, not as a competitor to other any other chipset manufacturer's design. This is probably why it's difficult to get an AMD employee to tell you what I've just said.

Some of AMD's stated goals are to promote the Socket 7 infrastructure that the AMD-K6& documents,

"VIA's industry-leading technology served as a basis for the AMD-640& the product's development and time to market& strategy is to assist third-party vendors to include leading-edge features in their products, to augment their chipsets with AMD-developed chipsets, and to optimize processor/chipset architectures to achieve highest performance solutions."

AMD has no plans for a Pentium Pro (Socket 8) chipset, as only Intel will probably ever create a Socket-8 compatible CPU. The same could be true for Slot 1, another design patented (and therefore proprietary) by Intel. It's unlikely AMD or anyone else will ever license Socket 8 or Slot 1 technology.

AMD's chipsets were supposed to include AGP support by 2H97, although nothing specific has been released officially. Word on the street is that VIA and AMD parted ways, and that AMD might get out of the chipset industry very soon. I also heard that AMD has no rights to VIA's Southbridge, the AMD-645 chip. Without this chip, AMD will be hard-pressed to make much of any impact on the chipset market.

No matter how AMD got into the chipset business, it seems that their AMD-640 is at least as good as the Intel 430TX and 430HX.


SiS is the second-largest chipset manufacturer, although this seems to be changing very quickly. Their chipsets are often the ones that have a shared memory architecture, which allows on-board video controllers to access main memory. Up to 4.0 MB of RAM can be shared, in increments of 0.5 MB. This type of video adapter uses "Unified Memory Architecture" or UMA.

Their 5597 chipset is PC97 compliant and sports an integrated video adapter. This targets the OEM's who would have to buy a video chipset anyway, since most of them put video on-board right now.

SiS is just now competing head-to-head with Intel, after a few years of being the "alternative" chipset manufacturer.


They are the chipset maker that should've, could've, would've been the best. They easily beat Intel's prices and had good features a few years ago. But their chipsets were plagued with problems and the fact that Intel thrust PCI on the scene faster than OPTi expected. Lately, OPTi has been making chipsets for low-end OEM systems and motherboards.

I think their "Vendetta" chipset is laughably the chipset that was too little, too late. Yes, they certainly must have a vendetta against the world's largest chipset manufacturer that came along and undercut OPTi's entire Pentium-chipset line. OPTi had some major regrouping to do after the Tritons came along. Saying all that, the Vendetta 750 looks like the Intel 430VX on paper, with a few exceptions: up to 512 MB of memory, UMA (Unified Memory Architecture) video support, ECC/parity support, and up to six banks of 72-pin RAM or four SDRAM modules. They apparently sell their chipsets in a package that includes the UMA video adapter and sound card.


The company with the worst reputation in the chipset community is PCChips. They were responsible for the "fake cache chip" fiasco that you can read all about here. They have been making chipsets for longer than I can remember, as I know that I've seen 386 motherboards with PCChips chipsets. They are related to Hsing Tech, who is a motherboard manufacturer.

Recently, I've been seeing more and more VXPro and HXPro chipsets appearing on cheap Socket 7 motherboards, and I have reason to believe that PCChips is the manufacturer of the chips.


Although ALi has been making their own chipsets for awhile, they are not well-known, nor are their products. Acer Laboratories is a small part of Acer as a whole, and they usually only make chipsets for the Acer and AcerOpen motherboards. Their Aladdin III and IV products are competitive with Intel's 430VX and 430TX chipsets.

Recently, I found out that ALi may be responsible for the HXPro and TXPro chipsets. From my conversations with some industry insiders at Comdex, I seriously doubt that anyone of my nationality will ever figure out this PCChips mystery. But as far as I can tell, ALi, SiS, and VIA are all in some way connected to PCChips' "Pro" chipsets which are probably made alongside the regular chips in the same fabs. The guy at SiS noted that the chipsets with a Roman numeral "II" were all SiS products.


  1. Introduction
  2. What Is a Chipset?
  3. A Brief History of Pentium Chipsets
  4. Triton: It All Started Here
  5. Intel Pentium Chipsets
  6. Non-Intel Pentium Chipsets
  7. Pentium Pro/II Chipsets
  8. The $69.00 Motherboard
  9. High-End Chipsets