Core 2 unlocking

G

GT

I've been reading around the subject of overclocking Core 2 Duo chips and
they seem to be very overclockable, yet are multiplier locked (except the
expensive x6800). The e6300 for example runs normally at 7x266.6, but can
cope with a FSB up to 450+, sometimes at stock voltages. However, this all
relies on an expensive and reliable motherboard that can also cope with such
a high FSB. It would appear that the voltage needs to be increased on the
motherboard chipset in order for it to operate at these higher FSBs. So this
immediately pushes up the price of the motherboard, counterbalancing the
cheaper processor + faster FSB.

It seems to me that increasing the multiplier and leaving the FSB somewhere
around 'normal', would mean the chips would run significantly faster on a
cheaper motherboard.

Not saying its a cheap board, but there is a BIOS update for the Asus P5B
motheboard that adds multiplier unlocking to some versions of the core 2
processors. Some processors can only run at higher multipliers and other
only lower, but either way, this leads me to believe that the multiplier
lock is software / firmware based, so could be by-passed by a pin mod or
some other method and achieved on budget motherboards.

However I cannot find any reference to pin mods that change the multiplier -
only voltage pinmods. Does anyone have any comments on this or know links to
methods to manually / physically adjust the multiplier on a Core 2 Duo chip.
 
K

kony

I've been reading around the subject of overclocking Core 2 Duo chips and
they seem to be very overclockable, yet are multiplier locked (except the
expensive x6800). The e6300 for example runs normally at 7x266.6, but can
cope with a FSB up to 450+, sometimes at stock voltages. However, this all
relies on an expensive and reliable motherboard that can also cope with such
a high FSB.

I would hope any board you buy, overclocking or not, was
reliable.

Expense is relative, there are some cheap boards that will
overclock too, it depends a lot on the chipset you have on
it.


It would appear that the voltage needs to be increased on the
motherboard chipset in order for it to operate at these higher FSBs.

You are seeing black and white instead of shades of grey.
Past a certain point yes, you'll need more voltage. Rather
than a problem, see it as an opportunity, you don't HAVE to
overclock that far and you don't HAVE to spend a lot. If
you were going to spend a lot you might just get a faster
CPU. You're drawing conclusionsn too quick though, a lot
of lower cost boards o'c ok.


So this
immediately pushes up the price of the motherboard, counterbalancing the
cheaper processor + faster FSB.

Yes, but not as much as you're making it out to be. I
suggest you pick a board based on features, besides
overclocking, and go from there. Plenty of people overclock
fine without buying the premium boards. To get a great
result you may need a moderately good to premium heatsink
though, but that is a good investment anyway because such a
heatsink allows lowest noise:temp ratio possible, even at
low to no overclocking.


It seems to me that increasing the multiplier and leaving the FSB somewhere
around 'normal', would mean the chips would run significantly faster on a
cheaper motherboard.

No, you'd still want to raise the FSB. You are trying to
out-think reality here, without having the parts to gain the
experience first... the experience you need to draw the
conclusions.

The bottom line is that even if you can't hit 40 gazillion
MHz FSB, you might still be able to hit 38 gazillion.
People brag about the highest overclocks, and the obscene
amounts of money they spend, but that doesn't mean it is
required. They brag BECAUSE they spent a lot, not because
it is necessary.

Anyway, pick a board that has the voltage adjustments and
the other features you want. Go from there. Overclock it
by rasing the FSB, though you will want reasonably good
memory but top-shelf isn't always important either.

Not saying its a cheap board, but there is a BIOS update for the Asus P5B
motheboard that adds multiplier unlocking to some versions of the core 2
processors. Some processors can only run at higher multipliers and other
only lower, but either way, this leads me to believe that the multiplier
lock is software / firmware based, so could be by-passed by a pin mod or
some other method and achieved on budget motherboards.

However I cannot find any reference to pin mods that change the multiplier -
only voltage pinmods. Does anyone have any comments on this or know links to
methods to manually / physically adjust the multiplier on a Core 2 Duo chip.

Are you aware that the whole point to the P5B unlocking is
to lower the multiplier so you can run at even higher FSB,
not lower, than the FSB rates you are trying to avoid?

Anyway, the method of changing the multiplier is to write a
different value to a model specific register... it's a
software, not a hardware hack per se. You can't manipulate
the pin logic levels to get anywhere like you could back in
the Pentium 1 days... or for past Athlons/etc.
 
E

ElJerid

GT said:
I've been reading around the subject of overclocking Core 2 Duo chips and
they seem to be very overclockable, yet are multiplier locked (except the
expensive x6800). The e6300 for example runs normally at 7x266.6, but can
cope with a FSB up to 450+, sometimes at stock voltages. However, this all
relies on an expensive and reliable motherboard that can also cope with
such a high FSB. It would appear that the voltage needs to be increased on
the motherboard chipset in order for it to operate at these higher FSBs.
So this immediately pushes up the price of the motherboard,
counterbalancing the cheaper processor + faster FSB.

It seems to me that increasing the multiplier and leaving the FSB
somewhere around 'normal', would mean the chips would run significantly
faster on a cheaper motherboard.

Not saying its a cheap board, but there is a BIOS update for the Asus P5B
motheboard that adds multiplier unlocking to some versions of the core 2
processors. Some processors can only run at higher multipliers and other
only lower, but either way, this leads me to believe that the multiplier
lock is software / firmware based, so could be by-passed by a pin mod or
some other method and achieved on budget motherboards.

However I cannot find any reference to pin mods that change the
multiplier - only voltage pinmods. Does anyone have any comments on this
or know links to methods to manually / physically adjust the multiplier on
a Core 2 Duo chip.

I remember in the good old times of the Pentium 4 Northwood, there was a
corner pin which controlled the overclockability of the cpu. Some
manufacturers removed this pin to avoid overclocking of their systems.
This feature was documented in an Intel white paper. Perhaps there is again
some info to find on Intel's site? documented
 

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