BIOS
Previous XPCs, whilst supporting a robust BIOS, generally let themselves down on the voltage front. The thinking behind this was sound. You'd not really want to add extra heat into a machine that's already got poor air circulation. Some argued that voltage should be allowed, and it should be up to the individual to decide just how much they apply. Shuttle, it seems, have listened to the latter group with the SB61G2's BIOS. Let's have a look.
The CPU clock ratio will only be visible if the CPU is unlocked. Our test 3.0GHz P4 'C' is unlocked from 12-15x. The CPU section is just like any full-size board's. You can either let the BIOS do the work or you can define the settings yourself. The CPU's FSB is another versatile affair, going from 100 - 255MHz in 1MHz increments. Shuttle have also provided an AGP/PCI/S-ATA frequency manipulation but running anything other than stock is a little pointless. Other options include 73/36/100MHz and 80/40/100MHz.
We touched on voltages at the top of the page. Shuttle have ripped out one of their standard ATX mainboard BIOSes and transplanted it to this XPC. CPU voltages have a broad range of options from 1.1v to 1.85v in 0.025v increments. DDR voltage goes up from the stock 2.5v (even though many boards consider 2.6v stock for DDR-400 speeds) to 2.75v. Lastly, you can see the slight increase afforded to AGP voltage. That's an impressive range for a PC not designed specifically for overclocking.
Changing DDR latencies actually does cause a distinct change in benchmark performance. We've seen a number of retail Canterwood-based boards that simply lock-out the DDR latencies at DDR-400 speeds on the assumption that manual timings may cause unwanted instabilities. BTW, if your RAM isn't quite up to it, the SB61G2 gives you the option of running it asynchronously at DDR-320 (5:4 ratio) and DDR-266 speeds (6:4 ratio). You can, of course, run 100FSB and 133FSB processors too. At the bottom of the above screenshot, you can just about see an option for the on-board video. The i865G sports the new Intel Extreme 2 integrated video, which appear to be fundamentally the same as the previous generation's.
The ICH5 use Parallel and Serial ATA technologies in hybrid fashion. The Disabled option disables the S-ATA option and sets the XPC up for standard P-ATA running, unsurprisingly. Combined mode gives you a total of 2 channels (4 drives) split anyway you like, either S-ATA+P-ATA or just S-ATA or P-ATA. Enhanced mode opens up both S-ATA and P-ATA with a possible 6-drive combination (2x SATA + 4x PATA). S-ATA-Only should be self-explanatory.
Under-load voltage can be best termed reasonable. Heavy OS load saw the board's VCore fluctuate quite heavily. Stability was good, however. We're not too sure if you'd really want to add further voltage to what is an undernourished PSU. The temperature monitor didn't seem too believable. It's difficult to see how a slimline cooler could keep a 3.0GHz P4 below 47c load temperature. Some surprising options for an XPC machine. We're relatively happy with it.
