For this review, we used two processors for our overclocking experiments with the VA6. We used an Intel Pentium III 550E and an Intel Pentium III 800E. We managed to overclock the 550E to a very respectful 825 MHz at 1.75 volts using the max bus speed of 150 MHz. We didn't have much luck with the Pentium III 800 as we were only able to bring it to a stable 840 MHz.
In order to bring a processor such as the 550E to
825 MHz, you have to take a few things in consideration. First and foremost is
having good quality PC-133 RAM. The RAM went up to 150 MHz with absolutely no
problems. Here's where the cool part comes in. Even if you don't have good
PC-133 RAM, but you happen to have good PC-100 RAM, then you are in luck.
You see, the VA6 has a very nice setting in the BIOS which allows you to run the RAM asynchronously from the FSB speed. In other words, you can run your RAM at +33 or -33 MHz from the FSB speed. For instance, if you are running an FSB of 150 MHz and you set the RAM speed at -33 MHz, then it's going to be running at 112 MHz, which is definitely a speed good PC-100 RAM can handle. Running your RAM slower than your bus speed is certainly going to impact performance, but sometimes such measures are necessary. We even came in contact with some PC-133 RAM that was not able to reach 150 MHz so not all RAM is created the same.
most important thing you have to take in consideration is your AGP speed. In
440BX based motherboards, the only AGP setting you have is either running your
AGP video card at the same speed as your bus or turning down to two thirds of
your bus. This setting will suffice at bus speeds lower than 133 MHz, but when
you start talking 150 MHz bus speeds then you are looking to be running your AGP
bus at 112 MHz, which is certainly a speed that most video cards will not
handle. We ran into this very same problem with both our Voodoo 3 and TNT2 Ultra
Windows loaded up just fine, but every time we decided to abuse the video card we got "blue screens of death". In this case the VA6 has got you covered also. There's a setting in the BIOS to completely disable AGP 2X support. So in essence you are cutting your AGP speed in half. So with a 150 MHz bus you are looking at a 75 MHz AGP speed which is definitely a setting most video cards will handle.
The VA6 certainly sounds like a great overclockers board. There's no doubt about it. One complaint I had was not having bus speeds higher than 150 MHz. I would have liked to see 155 or 160 MHz speeds.
"So what's the catch?" you ask?
The VA6 has a lot of "Good" but it also has its share of "Bad". It's performance
is certainly not up to par with similar 440BX motherboards. The poor performance
is not an issue with the motherboard but more like a problem with the chipset
that it's based on. It's no secret that Apollo 133 based boards are not as fast
as their 440BX counterparts. Let's take a look at some performance numbers.