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- 533MHz p4 @ 800MHz
- Martin Pick
May 8, 2005, 2:40 pm
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will a 533mhz p4 (northwood or prescott) handle running at 800mhz fsb? i ask
cos i have a m/b that only supports 800mhz p4`s and thort it would be a good
o/c. was looking at getting a 2.8ghz @533mhz chip and seeing what it came
out at. Are p4`s multiplier locked like amd`s? i ask as i have no experience
with p4`s. It would be about a 50% overclock and i presume a prescott would
run very hot at those speeds.
probably ben asked many times, so i apologise in advance :-)
Re: 533MHz p4 @ 800MHz
All Intel CPUs since the Pentium II 300 are multipler locked. The
multiplier CAN NOT be unlocked.
Pentium 4 CPUs are multiplier locked.
The multipler for a Pentium 4 2.8 GHz is 21X = (21 X 533/4);
with a front side bus of 800 MHz, the results would be 21 X 800/4 = 4.2
That is not going to happen.
Why not get the correct motherboard (a motherboard with an 800 MHz FSB
capability) and overclock by raising the FSB, like everyone else who
overclocks Pentium 4 CPUs? Generally the FSB is raised by steps until the
system does not operate in a stable fashion, then the CPU core voltage is
raised by a very small increment. These two steps are repeated until a
limit is reached. At that point a decision has to be made about improved
cooling (is it worth the extra cost?)
Pentium 4 motherboards made for overclocking have a lock that keeps the AGP
and PCI buses locked even when the FSB is changed from spec.
Because the FSB can be changed without affecting the operation of anything
connected to the AGP or PCI bus, overclocking by raising the FSB is very
easy IF the installed memory can operate at the increased clock speed.
Raising the FSB above spec gives a double benifit: the CPU speed is
increased AND the memory bandwidth is increased.
Pentium 4 Prescott CPUs run hot at ANY speed.
I think you should read some of the previous posts in this newsgroup and
items at various overclocking websites before making any decisions.
You could make your question more clear by adding information
the primary objective: to get the 'most bang for the buck OR to get a
record setting overclock
the intended use of the system
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