BIOS
SOYO's in-house COMBO BIOS impressed me when I reviewed the P4X400 DRAGON a few weeks ago. It appears that it's largely made the transition over to the KT400 variant intact. It adds a few new twists to a proven formula. Let's have a look.
Here's where the real action takes place. System performance can be set to a number of pre-defined settings. 'Normal', 'Fast', and 'Turbo' options are present. Each one sets the system RAM's timings to varying degrees of strictness. Turbo, naturally, is the one you want if you're after maximum performance. The CPU's FSB goes all the way up to 255MHz in 1MHz increments, a little hopeful. You can see some of the features at the bottom of the above picture.
The CPU:FSB dividers are out in force here. You can manually choose the following:
What that equates to, in layman's terms, is your system in perfect specification at 100FSB, 133FSB, 166FSB, or 200FSB respectively. Now we have to ask ourselves whether your RAM or chipset gives out first. Voltages are good too. CPU goes up to a respectable 1.85v, DDR to 2.8v and VAGP to 1.8v. I like the fact that you're shown the relative PCI and AGP speeds when you key in a certain number. That takes some of the guesswork out of overclocking.
DRAM timings are extremely adjustable. You can see the number of options above. I've set the RAM to the above settings for benchmarking purposes. The DRAM clock can be set to either SPD, 133, 166, or 200MHz, although the latter is not officially supported. Further, testing using the DDR400, once again, showed benchmark results lower than DDR333, even when set to CL2 mode. It seems as if the chipset simply doesn't like memory being run asynchronously at DDR400. Thinking of it from a technical sense, running DDR400 wouldn't give us much of a boost. After all, the Athlon is limited to DDR266 (XP2600 (333), 2700, and 2800 excepted).
A couple of things of note here. Firstly, we have 2 readings for the CPU temp, one from an external and one from an internal on-die probe. The latter, which is probably more accurate, differed from the external probe by as much as 10c. You can also set the motherboard to switch off at pre-defined temperatures.
Overclocking
Using a standard AMD XP2400, one that is unlocked by the majority of KT400-based motherboards, I tried selecting lower multipliers. Finally, after much head scratching and tinkerking, the SOYO rebooted with the chosen multiplier. Trying to run at 12*166 (2GHz) proved impossible, the SOYO simply refused to boot even with the /5 divider chosen and implemented, thereby keeping the PCI and AGP buses in specification. I couldn't get the chipset much past 150FSB without it locking on bootup. So the dividers may be present for sky-high FSBs, but it appears as if this particular chipset isn't. That's kind of disappointing from an enthusiast's point of view.
We'll have to investigate this further when we have a bona fide 166FSB Athlon processor in the labs.
