Before going over to the benchmarks, I would like to give you a brief description of the test methods. First of all, we will try to see whether the mainboards could make an Athlon XP 1700+ start up and work at 2250MHz (166x13.5, “2800+” rating) with 1.85V Vcore. Thus, we will check the ability of the mainboard to support high-end AMD processors, even with some reserve left. The system stability was tested with 3DMark 2001SE tests and dm-antalus from UT2003 Demo. If the mainboard fails to work properly, we have milder testing conditions: 2167MHz with 1.8V. To clear any doubts about sufficient cooling and other things, I’d like to say that these testing conditions were checked on one of the participating mainboards beforehand.
The second check is more traditional: we will reduce the CPU multiplier and will be increasing the FSB frequency until the system becomes unstable. Note: KT400A doesn’t suit for FSB overclocking as it has AGP and PCI frequencies dependent on the FSB frequency. It means we are likely to reach the top of supported AGP frequency rather than the mainboard stability peak.
Unfortunately, I cannot present any overclocking results for the DFI mainboard. This product was unstable in its regular mode, not to mention the results during overclocking. I suppose there is a faulty component on the mainboard, preventing it from proper operation, though, I can not provide any solid proofs for this assumption.
Anyway, I was unable to make the mainboard work stably in any mode and, again, you won’t see it in the tables. It’s rather sad, as it looked a promising product to me.
Now, let’s get to the tests.
The first test proved impossible to pass for some mainboards. The first one to fail is Soltek that couldn’t start the CPU as 2800+ with 1.85V Vcore. The system was only stable when I reduced the frequency to 2167MHz (“2700+” rating), but still with certain issues: the hot restart (from Windows) sometimes led to system’s freezing during the POST. In this case, even the Reset button did not help, and I had to power the system off and then on again. This problem vanished after the frequency dropped to 2083MHz (2600+).
The second unlucky participant is, surprisingly, the AOpen mainboard. Notwithstanding its cool power supply circuit, this mainboard could only work properly with the CPU overclocked to 2600+ rating with 1.8V core voltage. However, this one was somewhat better than the Soltek board: it could work stably with 2800+ CPU, but had the same hot restart problem.
The Gigabyte mainboard didn’t pass in this test. First, the mainboard determined the CPU frequency and didn’t allow clocking the system bus over 165MHz (in our case). Second, 7VAXP-A Ultra simply cannot set 1.85V or 1.8V core voltage. The maximum you can get from the mainboard is 10% above the nominal voltage, which is 1.5V for our Athlon XP 1700+. So, the overclocking capabilities of this mainboard remained a mystery. However, judging from the voltage range and FSB frequency setup approach, they wouldn’t present us anything exceptional.
The remaining mainboards, those from ABIT and EPoX, passed the test quite well. EPoX mainboard, that uses two-channel CPU voltage regulator like the board from Soltek, shows that the quality of the channels is as important as their quantity.
The results of the second test were more or less predictable: all mainboards notched somewhere around 175MHz, which proved that you shouldn’t use a KT400A-based mainboard with RADEON 9700 PRO for bus overclocking, at least in the AGP 8x mode. Maybe reducing the AGP speed to 4x could allow you to reach higher operational AGP (and, accordingly, FSB) frequencies. Once again, the Gigabyte mainboard didn’t take part in these tests as it couldn’t increase the bus speed above 165MHz.