BIOS
MSI once again turn towards AMI for BIOS duties. Let's have a look at the main configuration screen.
The 1.6v Vcore shown is the maximum permitted amount for most Pentium 4 Northwood CPU (the 2.66 and 2.8GHz processors have a default voltage of 1.525v, thus allowing 1.625v maximum Vcore). The extra 0.1v Vcore above default is relatively poor with respect to today's motherboards, especially as all motherboards tend to undervolt a little when put under stress. I had hoped to see an option allowing 1.75v Vcore. DDR memory voltage, however, is a little better at 2.8v from the default of 2.5v. Running memory at DDR400 speeds may just require a little extra juice.
SiS-based motherboards usually have a dazzling array of CPU to DRAM ratios, ensuring you get the most out of your DDR memory. Although the chipset, and by very definition this motherboard, only support DDR266 and DDR333 memory, you are provided with a quite bewildering range of ratios to choose from. Just some of those included are shown below.
The 3:5 ratio, if the processor is at 133FSB, will give you a DDR speed of 200MHz. Similarly, the 4:5 ratio will give you 166MHz, or DDR333. You can calculate each ratio quite simply. One advantage that most of the i845E chipset motherboards have enjoyed is the ability to lock the sensitive PCI and AGP busses at their default speeds of 33MHz and 66MHz respectively when overclocking your processor. This feature seems to have made the transition to this SiS648 motherboard.
You can choose various ratios as you best see fit, although I wouldn't waver from the 66/33 default speeds.
We have a little memory voltage to play with, so just how well can we manipulate the timings ?. Reasonably extensively, it seems.
DRAM latency can either be set to 2 or 2.5 clocks, with 2 clocks being the better from a performance point of view. Unlike some motherboards that give you specific timings for the various constituents of RAM, we get pre-defined timings of 'safe', 'normal', 'fast', 'turbo', and 'ultra'. You need some high-quality RAM to be able to run at Ultra timings. We also have a command rate selection of either 1T or 2T, with the former being the better and more RAM-taxing. During testing I was able to run a module of Mushkin PC3200 at CL2, Ultra and 1T timings at 166MHz (supported), and CL2.5, Fast, and 1T at 200MHz (unsupported).
Our audio and USB2.0, two of the more notable options, can be toggled on/off within BIOS. The rest of the BIOS is generally standard fare.
