X-bit labs

Contemporary Socket A Chipsets: NVIDIA nForce2 Ultra 400, NVIDIA nForce2 400, SiS748 and VIA KT600 (page 4)

Category: Chipsets

by Ilya Gavrichenkov

[ 07/08/2003 | 01:26 PM ]

Closer Look: SiS748

A new chipset from SiS supporting Athlon XP processors with 400MHz bus, SiS748, is also not a brand new solution in reality. In fact, SiS748 is the same SiS746FX with the official support of 200MHz FSB. As you remember, SIS746FX was a derivative of SiS746, which acquired official DDR400 SDRAM support. That is why SiS748 has no new peculiarities from the technological point of view.

As for the performance of the new SiS chipset, it is positioned as a solution for low-cost systems. However, we remember very well SiS735, which used to be the fastest Socket A chipset for a while. That is why we wouldn’t make any forecasts, as SiS748 can prepare us any sort of surprise.

HyperStreaming technology implemented in the new chipset is something SiS is especially proud of. This name hides the MuTIOL 1G bus with 1GB/sec bandwidth and highly original working algorithm, which connects the chipset North and South Bridges. The peculiarity of this bus is a separate independent stream, which is assigned for each request coming from the North Bridge resources to South Bridge resources (or vice versa). As a result, the latencies grow much lower and the requests can be deeply pipelined. However, we could hardly call HyperStreaming a revolutionary technology. Unfortunately, it will influence the overall system performance just a little.

Although SiS748 is a new chipset, it also doesn’t have SerialATA support, like NVIDIA nForce2 400. SiS engineers were probably a little lazy that is why they provide their solution with a relatively old SiS963 South Bridge (or SiS963L without IEEE1394 support). However, the company also offers a SiS180 companion chip together with the new SiS748, which is a separate PCI SerialATA controller supporting RAID. Anyway, bearing in mind the primary target of SiS748 based mainboards, we really doubt that SiS180 will be that widely spread.

Other than that SiS748 is a pretty common single-channel Socket A solution supporting new processors with 400MHz bus, DDR400 memory and AGP 8x.

SiS748 based reference mainboard.
The PCB didn’t change since the times of SiS746.
Also note that there is no heatsink on the chipset North Bridge:
the chipset hardly gets warm at all.