SiS 756: PCI Express for AMD Socket 939

There is no doubt that NVIDIA's nForce4 chipset is the standard against which AMD Socket 939 chipsets will be measured. AMD has become the leading enthusiast platform and NVIDIA's chipset fortunes have risen while VIA has continued to struggle in this arena. There are many companies who want a piece of that growing chipset pie, however, ranging from large players like ATI to relative newcomers like ULi.

In recent weeks, we have been looking at these contenders. The first production ATI board aimed at the enthusiast was reviewed in Sapphire PURE Innovation - ATI's Chipset for the AMD Enthusiast . The Multi-GPU ATI Crossfire board will launch later this month. ULi provided two generations of Socket 939 PCIe Reference boards in FIRST LOOK: ULi M1695 PCIe/AGP Socket 939 for Athlon 64 and ULi M1695 PCIe/AGP for Athlon 64 - Part 2 with SLI. This led to a review a few days ago of the first production ULi M1695/M1567 in ASRock 939Dual-SATA2: First Retail ULi PCIe/AGP. Since we found many good things in the new Socket 939 chipsets, we decided to take a closer look at another contender - the SiS 756 chipset.

The SiS 756 is an upgrade to the SiS755FX chipset that we reviewed last December. Where the 755FX was PCI/AGP, the SiS 756 was to feature the PCI Express bus with PCIe graphics. The SiS 756 first appeared as Reference samples to reviewers many months ago, but the retail products have taken a long time to appear in the market. Our readers will likely advise us of other offerings, but almost 6 months after review samples, we could only find one production SiS 756 board, the ASRock 939S56-M, and even it is difficult to find. We also discovered that the ECS PF88, the ECS modular CPU board discussed in Editors Day 2005: A "NEW" ECS Looks to the Future, uses the SiS756 on the A9 add-on module for Socket 939. We could not find any other current production boards using the SiS 756 chipset.

So, how does SiS 756 compare to nForce4, ATI Rx480, and ULi 1695? Is performance on par with the best Socket 939 chipsets? Are features competitive in the Socket 939 universe?