Stupid OC question

[Antisocial Virge]

I just got a 1.2 266 AXIA and its running at 10.5 at 133fsb at 1.76 vcore so thats 1400 Mhz which is fine by me. The question I have is why do some people OC using the FSB? I see people lowering the multiplier and upping the FSB to get to the same Mhz. For example what would be the advantage of me dropping back the multiplier and upping the FSB from what I have now?

Like I said probably a stupid question.

On a side note I'm running 3 hd's, 3 cdroms and 3 case fans and this overclock all on a 300 watt PS :Q
think I'm pushing the limit much?

 

[bacillus]

higher memory bandwidth!

 

[Greymalkin]

overclocking FSB gives u better overall system performance, if u only use multiplier, then u only overclock your CPU, if u use FSB then u can sometimes get your memory to the equvelent of PC165!!! (rare) However this is more likely to make a system unstable. Also those with 100MHz bus with a 1.3 GHz on a KT7a Raid cant up there multiplier further than 12.5 ( the bios automatically does it above this.) so they need to be use FSB to oc.

 

[crawfish]

By overclocing FSB you are overclocking not only your CPU but also your system memory, AGP device, PCI device, hard drive, etc. In many cases, these are where the performance bottleneck lies in, therefore you can get better performance boost by overclocking FSB.

 

[Wind]

Have to warn you that O/Cing FSB could cause system instability. O/Cing multiplier is much safer. Obviously, O/Cing FSB will increase performance more than the multiplier. If you wanna O/Cking the FSB, make sure you do it slowly (incremental of 1 Mhz at a time). Then test the system for stability.

 

[Archknight]

overclocking FSB give a higher performance boost than multiplier.

 

[Mer]

Here's an example:-

10 x 100Mhz = 1000Mhz (100Mhz FSB)

Now let's lower the multiplier from 10 to 7.5 and up the FSB from 100Mhz to 133Mhz.

7.5 x 133Mhz = 1000Mhz (133Mhz FSB)

In essence your CPU is still running at 1000Mhz (1Ghz) but you have the benefit of the 133Mhz FSB now. So you have more memory bandwidth etc. and less stress on your CPU.

Now if you can keep the multiplier at 7.5 and raise the FSB even more... then you get even better performance

I hope this helps!!

Sweetess,
Mer.
PS: Do all this at your own risk... hehe just had to add that little disclamier

 

[heffe734]

OCing fsb does make the system more stable...i'm having problems OCing fsb as well...even tho the epox 1/5 divider kicks in...i dropped the muliplier to 10 and bumped it up to 167 and 9.5 x 167...both didn't posted...it's weird cuz 11.5x145...i can hit 1.67 and run it stable.

I think you might need a lil more juice..try investing in a 400 W PSU.

 

[Antisocial Virge]

Thanks alot. I kinda thought it had something to do with memory bandwidth. Heard that mentioned more than once. I never tried pushing the FSB yet cause I remember crunching an old maxtor when I hit 83 fsb on a old celeron system Ever since then I have followed the "Multiplier good...FSB bad" idea 1400 seems fast enough for me.

I plan on getting a bigger PS eventually but I'm surprised its running so stable as it is now.