newb questions - AX63pro/c366. h-drive? pci clock ?

hello, i am new to overclocking. hopefully i'm in the right forum - i didn't see a general beginners one. anyway, as i said i have an Aopen AX63 Pro, with a celeron 366.

my main question is: am i hurting my hard-drive, or other systems by overclocking? i'm currently at 78mhz, with no voltage increase. i've come across this scary warning:

http://www.kingvinnie.com/fastercomputers/overclocking/celeronfaq2.asp

"Be happy with what you can get and try the 75 or the 83 MHz bus. These non-standard bus speeds can really trash your hard drive due to the fact that the PCI bus is also being overclocked. The PCI is at its normal speed (33 MHz) when using the 66, 100 & the 133 MHz bus speeds. Be careful when trying 75 or 83 MHz and back up your data. Be prepared to reformat your hard drive if you encounter disk errors or other unexpected problems, especially at the 83 MHz speed. "

mysterious (to me) settings:

also, should i worry about changing the FSB/PCI clock ratio? the motherboard manual isn't very clear. it is set to 'auto' right now. but i can manual set it to 2x or 3x. any opinions? i can provide more details from the sparse mobo manual if you'd like.

cooling:

at first i was going to put one at the bottom front and one at the top back. but then i realized that would result in a dusty negative case pressure (1 in, 2 out). so i've added a suckhole to the side of the case, bring fresh air directly to the cpu. it stays usually around 27 degrees C. so i suppose if necessary, my next fan will be a second intake fan, this on at the front, near the bottom but under the hard-drive. that way i'll get a positive case pressure (2 intakes, one exhause in the power supply). sounds good? or should i really be putting in that exhaust?

thanks,
charlie

My experience has shown that 75 FSB is easy on components. At this speed with the 1/2 PCI bus divider, your PCI will be at 37.5 MHz. At 78 FSB, the PCI bus is 39 MHz which might be getting sort of borderline stable. I've know lots of people who ran 83 FSB, but I usually had some stability problems when I tried running that speed. The worst problem I've ever had with a harddrive running out of spec was data scrambling. But, after backing off the overclock a little and then reformatting the drive, everything was back to normal with no permanent damage. That's what they meant by "trashing" the harddrive... data corruption and messing up Windows registry files. Backing things up is good advice.

As closer you approach 100 FSB, the more you will probablyl need to use the 1/3 PCI divider. There were some Celly 366 that could handle 100 FSB for a clock speed of 550 MHz. Probably will need exceptional cooling and a slight voltage increase.

I'd check temps and try various fan configurations and see what works best for you, but having an exhaust fan in the back near the CPU and an intake in the front lower part of the case has always worked best for me.