I have to admit, i am at a little bit of a loss when it comes to overclocking. Is there some definitive guide i can check out on how to overclock? I mean i want to know all the small details like if i was running an XP1800 on a 133Mhz bus, how would i use DDR333 at its correct speed? if i increased the FSB that would increase the CPU clock, so how do i get that back down to the default speed it should be...and then would that speed-up the PCI bus? if it would then how do i get it back down to the right speed...and what is the right speed for the PCI bus? so many questions and so few answers! please any help is really appreciated! thanks!
Phew. Lots of questions about OCing, but it is fun. There is no exact science to OCing though. The memory is usually kept in sync with the processor, but most new mobo's have the option to set the memory asynchronous with the processor so you can run the proccessor at 266 and mem at 333. When you up the FSB though, the memory will be OCed as well. Wether it be in sync or async with the processor. Example: Proc/Mem @ 133 and you up FSB to 145, Proc/Mem both go to 145. Proc @ 133/ Mem @ 166 and you up Proc to 145, Mem will go to 178. Always remember though, like you said, when you up the FSB, it will OC the PCI/AGP bus as well. The proper PCI bus speed is 33MHz and the AGP is 66MHz. Some mobo's, such as the Epox 8K3A+ has the proper divider's to keep the PCI/AGP bus speeds in order. Others, I can't remember specifics, automatically apply the PCI/AGP bus divider at a 166FSB, if the mobo will get that high and be able to POST and run. I hope that will clear up some of the mystery of OCing and speeds to you. There really is no definitive guide to OCing, but there are few out there. Search somewhere like Google to find them.
Your FSB speed is the CPU speed. So FSB of 133(266ddr) is CPU 133(266ddr), thus to get memory at 333(166ddr) you would set the CPU to Memory ratio at 4:5 ratio 133:166 = ratio 4:5 As you say increasing FSB will also increase PCI speeds, most if not all 333/400 mobo's have a 1/4 and 1/5 divider. ie FSB @ 133 PCI @33 RATIO 4:1 (1/4) FSB @166 PCI @ 33 Ratio 5:1 (1/5) Most mobo's only apply the divider at preset values such as 133 and 166, if you run at non standard speed ie 145 then you will be running PCI too high (something like 38mhz) this doesnt always effect components in a bad way, but there are a lot of reports that sound cards and nic's will start to act up. Pretty much what DJMyst said,
Here are a couple of guides that may be of use: http://www.anandtech.com/showdoc.html?i=1345 http://www.amdworld.co.uk/oc.htm
ok that makes sense, say i was running an XP1800 at its default speed of 1533 Mhz (with a multiplier of 133 x 11.5), and like the example above i upped the FSB to 166 ...that would mean the CPU speed would go up to 1909 Mhz which wouldnt be very stable. Would i then have to set the multiplier LOWER to x9 for example to bring the CPU speed back down to 1495 Mhz? Would i be able to do this because i thought most athlon XP chips are multiplier locked? also, if i did change the FSB up from 133 to 166, what dividers would i need to reset the PCI bus back to 33mhz and the AGP bus back to 66mhz? ALSO (sorry yet another question!), on my Iwill XP333, it has a jumper for 100 or 133Mhz FSB...now it also has a CPU Clock speed setting in the BIOS which you can increment by 1 Mhz steps...(currently set to 133) If i increase this, is it increasing the FSB or what? Can the FSB even be changed on this board since it has a jumper for either 100 or 133? so basically if i did as i described above i would safely have overclocked to accomodate for the extra bandwidth of DDR333? cheers for all your help
On most boards that I have seen with a 100/133 MHz FSB jumper, it needs to be set to 133 MHz to start at 133. The IWill XP333 will automatically detect what the processor is though won't it?? I did find a review here that states the OCing features of the IWill XP33 board. There is a 1/5 and 1/6 PCI divider, but no AGP divider. The dividers do have to be set in the BIOS though. The multipliers on the Athlon XP chips are locked and can't be changed w/o unlocking them also. You could probably get this board to OC to a 166FSB, but it will take some work. I doubt you could get the chip to go straight to 166FSB w/o lowering the multiplier though, and to do that, you will have to unlock the chip.
I'm not into overclocking myself but I have come across this site and it's written for beginners with no clue as to what they're doing http://www.overclockers.com/tips1039/ Have Fun
Nice guide Kronenbourg1664. I also remember when my dad used to drink that beer. Shame we can't find it here in the states anymore.
Good beer: Kronenbourg 1664, Stella, Fosters Bad Beer: Budweiser, Carlsberg, the stuff we had in poland.... EDIT: Is there actually such a thing as a 'bad' beer? Anyways, wandering wildly off topic...
