Gigabyte's GA-8S648FX Motherboard
Bridging the gap with the SiS 648FX

"Burned" in by Robert Maloney
August 13th, 2003

         

A lot of hype and controversy has surrounded Intel's latest chipsets, the i865 Springdale and the i875 Canterwood, and they are proving to be very capable solutions for the Pentium 4 processor. But the question remains to be asked; what have the other chipset designers been up to? We haven't seen VIA's latest offering make much noise, but SiS has kept forging ahead, looking to improve on their previous offerings. If you recall, we had a look at an MSI board based on the SiS648 back in late October of 2002, and it fared very well when compared to Intel i845PE based motherboards. We even went so far as to label it as one of the fastest DDR-based chipsets for the Pentium 4. Since then, starting with Granite Bay motherboards, dual channel DDR has become the norm, and front side buses have been pushed up to 800MHz. SiS went back to the proverbial drawing board, and tinkered with the 648 chipset to create the 648FX. The 648FX supports CPU Hyperthreading at 400, 533, and 800MHz FSB, and officially supports DDR400, but only in single channel configurations. Obviously, the memory bandwidth is therefore much lower than the Canterwood or Springdale, and they can't necessarily be compared head to head.. Instead, the SiS648FX can be considered something of a "go-between", offering an upgrade in performance over 845-based boards, but falling short of an 865/875. Gigabyte's GA-8S648FX is the first motherboard based on the 648FX that we have had in the labs. Is there enough power in this board to make this Giga bite?  Ouch, that was rough.

     
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Specifications & Features of The GA-8S648FX
What makes this board tick?

      
 

CPU SUPPORT

  • Intel Pentium 4 Processor with Hyper-Threading Technology

  • Socket 478 Pentium 4 Processors

  • Supports 800MHz, 533MHz or 400MHz Front Side Bus

CHIPSET

  • SiS648FX Host/Memory Controller - North Bridge

  • SiS963 MuTIOL Media I/O - South Bridge

SYSTEM MEMORY

  • Supports 3 x 184-pin DDR SDRAM

  • DDR266/333/400 support

  • 3GB maximum system RAM (unbuffered)

BIOS

  • Licensed Award BIOS

  • Supports PnP, ACPI, DMI, STR

  • 2Mbit flash ROM

  • Supports Q-Flash, @BIOS

HARDWARE MONITOR

  • System health status auto-detect and report by BIOS

  • Hardware detecting and reporting for case open, power-in voltage, CPU voltage, and fan speed.

AUDIO FEATURES

  • Realtek ALC650 v2.2 6-channel sound CODEC

  • Digital audio interface supports 24-bit S/PDIF optical in/out

 

PCI IDE INTERFACE

  • 2 IDE bus master (UDMA33/ATA66/ATA100/ATA133) IDE ports

  • Supports up to four ATAPI devices

  • Supports PIO Mode 3,4 Enhanced IDE and ATAPI CD-ROM

  • Bus mastering reduces CPU utilization during disk transfer

REAR PANEL I/O PORTS

  • 2 USB 2.0/1.1 ports

  • 2 DB-9 serial ports

  • 1 DB-25 parallel port

  • 1 mini-DIN-6 PS/2 mouse port

  • 1 mini-DIN-6 PS/2 keyboard port

  • 3 audio jacks: line-in, line-out,  and Mic-in

  • 1 Game/MIDI Port

I/O CONNECTORS

  • 2 connectors for 4 additional external USB 2.0/1.1 ports

  • 1 1394 pin header (supports 3 FireWire ports via optional daughter card S1394)

  • 1 front audio connector for external line-out and Mic-in jacks

  • 2 internal audio connectors (CD-in and AUX-in)

  • 1 connector for Surround/Center audio channel

  • 1 S/PDIF output connector

  • 2 IDE connectors

  • 1 floppy connector

  • 2 ATX power supply connectors

  • 3 fan connectors for CPU fan, NB fan, and chassis fan

EXPANSION SLOTS

  • 1 AGP 3.0 slot supports 8X/4X modes (1.5V support only)

  • 5 32-bit PCI 2.2 slots

FORM FACTOR

  • 4 layers, ATX form factor

  • 29.5cm x 20.9cm

   
 


Specifications of the SiS648FX
What's happening on the other side of the fence

SiS made a tidy little upgrade to their existing 648 chipset, adding support for 800MHz front side bus Pentium 4 CPUs and Hypertheading while keeping all of the good points intact.  Combined with DDR400 and AGP8x support, and SiS's proprietary MuTIOL interconnect between the North Bridge and South Bridge, the SiS648FX is poised as a high-end, low-cost solution for the mainstream user.  What SiS doesn't bring to the table, however, is dual DDR memory channels, which would have increased overall performance, and native support for Serial ATA or RAID configurations.  You might notice that 2 SATA ports are listed in the chipset schematic above, but these come at the price of a PCI-based SiS 180 Serial ATA controller.  Being PCI-based, this could lead to bottlenecks on the already burdened PCI bus.  From what we have heard, SiS' future plans involve a new SiS964 South Bridge, which should have SATA support built in, and is the logical choice for future revisions of the 648FX and 655FX.

Considering the features, the 648FX falls somewhere in between the older i845/SiS648 boards and the current crop of Springdales and Canterwoods.  So, on which end of the scale will it end up?  We took one company's SiS648FX board, the Gigabyte GA-8S648FX, and compared it to two boards from our Springdale Showdown to find out.  While doing so, we took one board, the Abit IS7-G, that comes with a PAT-like memory enhancement, and another board that didn't, the Chaintech Apogee 9PJL.  These two boards should give us a good idea of how the performance of the SiS648FX compares.

We take a closer look at the challenger