I just picked up a P4S533 from Multiwave for $108, came with 6-channel audio and LAN. I tested a 1.6a that was known to do 160 FSB, 1.8 volts on a P4B266-E, the best o/cing Northwood board IMO. Well it did 160 FSB also, but at a bit less voltage: 1.775. So for starters, it is a damn good overclocking board. I passed on the Epox 4DA+ or whatever because I felt few people were hitting 160 FSB or over.
One drawback is the BIOS only goes to 166 FSB, but if you don't have a chip that will clear that it's a moot point.
You can't lock the PCI, but I've been running my Ti 4600 overclocked to 315/730 at 160 FSB no problem. Everything is totally stable in 3D at 160, plus the board really has zip. Feels faster than my P4B266-E and P4T-E rigs overall. 3D motion seems a bit smoother although the benches don't show it.
One really great thing about the board is it has a built-in volt mod. When you change a jumper you get +0.2 volts at all BIOS settings, but in actuallity it is closer to .15. However this gives you 1.85 max in the BIOS, which is plenty enough for most people (I don't go over 1.8 myself). On both my P4B266-E and P4T-E I have to vid pin to get 1.8 volts.
There is a VMEM jumper to adjust DDR voltage from 2.5 default to 2.7 and 2.9.
I am using two sticks 256 MB Samsung PC2700 at DDR400, 2.5-2-2-6-AUTO settings. I use a 4:5 mem ratio at 160 FSB to get there.
This board has 1:1, 3:4, 3:5, and 3:6 dividers below 133 and 1:1, 4:3, 4:5, and 4:6 from 133 to 160. Over 160 it is just 1:1 and 4:3.
The board is very stable with no cold boot problem. So far I am pretty impressed with this SIS 645DX board, after using mainly Intel 478 boards.
