OC'd celery trashes my hard drive...

[_raziel_]

hey guys, i overclocked my celeron 366 up to 413 MHZ n everything went fine, cracnk it up to around 450, my system booted up fine but crashed upon loading windows, even trashed my hard drive. Im pretty much a newbie when it comes to OC'ing, can anyone tell me where i went wrong?

[krusty the klown]

The hard drive trashing could well be due to excessive PCI bus speed.

Your 366 has a multiplier of 5.5*, so it's normal operation would be 5.5*66MHz. At this setting the PCI bus speed will be 66/2 = 33MHz (normal)

To run at 450MHz, you would have run at 81MHz and your PCI bus speed would have been 81/2 = 40.5MHz.

Running PCI buses this much out of spec can cause HDD problems (especially with older drives), so your alternatives are to either drop back, check in your mobo manual / BIOS whether you can run these FSBs but run a different (slower) PCI bus by forcing a /3 divider for the PCI bus (giving 81/3 = 27MHz), you can also try disabling UDMA in BIOS or running a slower PIO mode for the HDD.

Usually, the BIOS defaults to autodetecting the PIO mode (you can find out what the PIO mode is during boot up). You could then go into BIOS and try forcing a lower PIO mode than your drive actually is.

This may sound odd, but you could also try running a 90 or 95MHz FSB if you have the option and if the CPU will handle ~500+MHz. At this FSB, the /3 divider is (usually) used and your HDD would not have a problem. You may need to increase the CPU core voltage to get it to run at this speed. Some boards let you, some don't and if you're running a socket 370CPU on a Slot1 board using a 'Slocket', some slockets have on-board CPU core voltage adjustment. 10% increase is considered safe, so stick to 2.2V max, but a retail heatsink may not be good enough, as the CPU will put out more heat at this voltage.

[Hellmund]

Krusty beat me to it;)

[_raziel_]

thanks guys, about the 90 - 95 FSB, i dont think my mobo supports that, i own an abit be6 btw. And i cant seem to find the option for the PCI divider anywhere. I'll give the PIO option a try :)