R658 - First Retail Application
While many have abandoned Rambus in favour of Dual Channel DDR SDRAM, SiS has kept its options opened to the rather unpopular memory technology. Rambus was left in the lurch on the PC front with its RDRAM memory technology after Intel moved away from the I850(E) chipset and embraced the DDR SDRAM I845 series, RDRAM was virtually left without a supporter. Once Intel's intentions towards RDRAM were made clear, Rambus moved on to find another possibility for their RDRAM systems. Rambus quickly negotiated with SiS to produce a RDRAM chipset that would support PC800, PC1066 and even PC1200 RDRAM modules. SiS just recently at Computex 2002 showed off the designs for their RDRAM support. The R658 is the first chipset to support RDRAM with PC1200 memory support. SiS also adds the AGP 8x transfer rate to this chipset, allowing for the latest ATI Radeon and nVidia GeForce video cards to operate at their full capacity. The R658 supports both 400/533MHz FSB and unofficial support for 800MHz FSB.
To give the R658 the best compatibility, the 963 Southbridge has been included in the package. The 963 Southbridge is no stranger to us, first seen with the 648 chipset solutions, it adds six USB 2.0 ports, two ATA-133 IDE ports, AC'97 Audio, 10/100 Ethernet and two IEEE1394a Firewire ports all on the one Southbridge. SiS has yet to introduce the 964 and 965 Southbridge's with Serial ATA, but as you will soon see ABIT solves this problem for us.
The Northbridge is cooled with a Crystal Orb like heatsink and fan combo. This has been used on other ABIT boards such as the AT7 Max and the NF7 series motherboards. This has proven to cool quite effectively.
While using the onboard SiS900 Ethernet that is supplied with the 963 Southbridge, ABIT prefers to take Ethernet to the next level. Gigabit Ethernet has become the new standard for hardcore LAN addicts. Most new LAN events are now upgrading for the Gigabit users and if you want the best in speed in the venue you need something like this.
ABIT has put the Broadcom Gigabit Ethernet controller onboard. Tied directly into the PCI bus you get 1GB/s across the network with compatible switches.
Serial ATA RAID Included
As stated above, SiS does not currently have a Southbridge solution that supports native Serial ATA.
For just about any new motherboard to keep up with the currant and future demands, Serial ATA is a must. ABIT have in the past relied on Highpoint IDE controller with the Marvel Parallel to Serial ATA converter chips to do its serial ATA needs. With tests showing that the Marvel converters slow down the Serial ATA transfers, ABIT has abandoned the converting methods supplied by marvel and gone with the Silicon Image 3112A Serial ATA controller chip to provide its SATA needs.
Unlike the Highpoint or Promise, Silicon Image is a dedicated Serial ATA controller; it generates Serial ATA signals rather than converting Parallel to Serial. Another feature is the ability to use this chip as a RAID system. This chip can either work in RAID 0, RAID 1 or 0+1 to allow for the best performance and/or redundancy.
BIOS and Overclocking
Like all of ABIT's true bread of overclocker's motherboards, the SI7-G uses a standard Award BIOS with the famous Softmenu III overclocking system. This was first introduced back in the Socket 7 CPU days to allow jumperless configuration of the CPU, it has now become an overclocker's delight and somewhat of a standard among most manufacturers.
Under the Softmenu Subsystem within the BIOS you can change just about every critical system for overclocking the system successfully. Setting the CPU parameters to User Defined allows you to change many options. First you have your CPU Front Side Bus which can be adjusted from 100MHz up to 250MHz in 1MHz increments.
Memory dividers can be changed for PC800/1066/1200 - These dividers are available and let you know what speed your memory is running at depending on the divider selected and FSB the system is running at.
CPU voltage can be adjusted from 1.5v up to 1.85v. This allows for the most overclocking out of your Northwood and Willamette processors.
RDRAM voltage can be adjusted from 2.5v up to 2.9v. This allows for better stability of the RDRAM at higher bus speeds. RDRAM is very sensitive to bus noise. Adding extra voltage helps when overclocking the memory above PC1200 specs.
Finally, APG voltage can be adjusted from 1.5v up to 1.8v. This is more than enough since the AGP/PCI dividers can be locked to 66/33MHz, respectively.