Overclocking

[JammyJim]

I successfully overclocked my machine from a standard 1737mhz to a breathtaking 1823 just by changing the speed of the mobo.

i changed the setting from 133 to 140mhz (141 worked but was highly unstable)

how will this affect things such as my geforce 4 mx420 and will it lead to the eventual meltdown of other pc parts....

atm its been toned back down to 1737 until i know the answer :-)

[Androme]

From I've learnt on cooling and then to O/c'ing, you should check the temperature of your mobo - check your BIOS and if it's above 50 *C (CPU Temp.) then there's a worry

if you've got an okish h/s/f then u should be ok

and if you're worried then u can go to www.quietpc.com and get their Mobo cooler chip

[meglamaniac]

If I remember rightly, increasing the FSB speed also increases the PCI bus speed so you can make your graphics card (and other expansion cards) unstable - before you ask the AGP slot speed is connected to the PCI bus.
It's a while since I looked into overclocking though, so I'd wait for someone more reliable to come along to confirm that.

Anyway, unless you see something wrong (such as display artifacts (squares missing, lines, corrupt areas, general 'badness') when playing games etc I'd assume things are going ok.

[pablissimo]

Originally posted by meglamaniac
If I remember rightly, increasing the FSB speed also increases the PCI bus speed so you can make your graphics card (and other expansion cards) unstable - before you ask the AGP slot speed is connected to the PCI bus.
It's a while since I looked into overclocking though, so I'd wait for someone more reliable to come along to confirm that.

Anyway, unless you see something wrong (such as display artifacts (squares missing, lines, corrupt areas, general 'badness') when playing games etc I'd assume things are going ok.

I don't think you have to worry about the other system components overheating if you up your FSB, more that either they'll become unstable or the processor starts making mistakes and sending the wrong instructions about the place, making the whole system unstable.

But if it's working without crashes, the only way is up, oooh, baby, for you and mee now.

[Luckeh!!!!]

I'll assume you are using an AMD CPU (1733Mhz = AXP2100+)

If you have an Nforce2 motherboard, the PCI bus is locked @ 33Mhz and the AGP can be set to what ever you wish (you can OC the AGP bus to around 70Mhz and be stable still with most GFX cards)

However, if you have any other motherboard (VIA, SIS, ATI) then you have to rely on dividers to keep your AGP/PCI bus within spec e.g. a 4/2/1 divider = FSB 133Mhz/AGP 66Mhz/PCI 33Mhz and 5/2/1 divider = FSB 166Mhz etc...

So therefore selecting either 133Mhz or 166Mhz FSB exactly will have the AGP/PCI bus running @ default speeds.

running for example 140Mhz FSB, your AGP is @ 70Mhz and PCI @ 35Mhz.

You are effectively OCing your HDD and PCI cards which is usually not good.

OCing have other limiting factors -

HEAT - Two areas, your CPU and your northbridge mobo chipset, these need to be adequately cooled for added stability.

Voltages - When you OC the FSB, you OC the main memory also, you might need to up the voltages on both the CPU and RAM in order to get a stable OC or to OC to higher FSB.

For your GFX card, OCing the AGP bus will increase GFX performance.

What ram do you have? If you have 333Mhz/166Mhz PC2700, the nyou could try unlocking your CPU and running the FSB @ 166Mhz but with a lower multiplier. So to get 1733Mhz with a 166Mhz FSB then you need to use 10.5 (10.5 x166 = ~1733), default is 13x133. This increase of FSB but maintaining default Mhz rating will yield an overall improvement of gaming performance.

If you don't want to risk the unlocking procedure then you are stuck with the FSB only.

[MT]

how to o/c, by MT

drop your multiplier down to 8, or as low as it can go

push your fsb up till it becomes unstable

drop back 2 MHz

raise your multiplier until it becomes unstable

drop back 0.5 X

smile

btw

someone explain to me how you overclock a hdd? HELLO LUCKEH!

I have an oldish board, and can reach 150 fsb with nae bother with 133 MHz rated CAS-2 crucial SDR SDRAM. I have heard of people in the 180's with ddr 266, so you really should be pushing it out (all with aircooling tbh) Find glimmerman or pabbeh if you want it explained properly, although pabbeh has to make do with what he steals for parts. dirty scouser.

[meglamaniac]

Originally posted by MT
someone explain to me how you overclock a hdd? HELLO LUCKEH!

Perhaps he means the IDE bus? But as far as I can remember that's handled by the chipset/northbridge so is unaffected isn't it?
I'm not too sure - the actualy motherboard architecture isn't my strong point.

As we have a Computer Architectures module coming up, I'm sure I'll have it comming out of my ears soon though.

[Luckeh!!!!]

When you OC the FSB (Front Side Bus, all buses), you are OCing EVERYTHING controlled by the northbridge (including the IDE bus), which is why you need good cooling on the northbridge because this can get quite hot.

EDIT - The IDE and PCI share the same bus.