BIOS, stability and overclocking
BIOS duty is handled by the very capable Award BIOS configuration utility. We're fans of Award's BIOS', so this came as a pleasant surprise.
Above is a screenshot of the main configuration screen. The Front Side Bus (CPU Clock) can be manipulated from 100 - 200MHz in one MHz increments, making the P4PA an overclockers' delight. CPU Vcore is also adjustable from 1.1v up to 1.85v in 0.025v increments. The very fact that we could select 1.85v for our P4 Northwood CPU, without the need for any external modification, reiterates the overclocking potential of the P4PA. DDR voltage is also adjustable from the default 2.5v up to a respectable 2.8v.
System memory can either be set to run synchronously to the CPU clock (100MHz at default), or asynchronously (133MHz) for PC2100 support. As you can no doubt see, memory timings are extensively modifiable. We've chosen what we believe to be the most performance orientated timings for our testing.
The usual gamut of options are present in the form of hardware monitoring, AGP, device and power management. Kudos to VIA for including a wide range of voltages that should satiate the needs of all but the most extreme of overclockers.
Stability was excellent. The P4PA was run with its strictest timings over a 24-hour period. Prime95, Quake 3 and Sisoft Sandra Burn-in were used to load the P4PA. In the entire 24-hour period we never received an unexpected error. If stability is your primary concern, then the P4PA will score highly.
We used memory modules from Crucial, Samsung and Twinmos in varying combinations. The P4PA worked flawlessly with each and every module. I tried different video cards and a number of PCI devices in different slots, again, not a problem in sight.
One aspect to note with almost all Pentium 4 motherboards is the voltage given to the CPU can be up to 0.1v less than set in BIOS. This is to be expected as it conforms with Intel's VRM 9.0 specification. Complying with this, the P4PA gives an average load voltage of 1.41v when set to 1.5v in BIOS.
The P4X266A chipset is purported to support the upcoming 533FSB Pentium 4 processors. With this in mind we set about overclocking the P4PA. We used an extremely overclockable 1.6GHz Northwood, one that has been perfectly stable at 153FSB, in another board.
Surprisingly, we could only get to 128FSB with decent stability. If we tried 129FSB, the P4PA would simply boot at 100FSB. Raising voltages made no difference. We tried 140 and 150 FSBs without joy. We feel that 129FSB is not a motherboard limitation, but rather a BIOS limitation, especially as we could get to 128FSB with less than default Vcore. We'll be investigating the overclocking matter in more detail later, and hope to update you of our findings. Let's now see what our benchmarking suite makes of the VIA P4PA.
