Replace 400 FSB CPU w/ 533 FSB CPU

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Hello ACHO Gurus,

Forgive me in advance if my post is inappropriate or misguided for this

I have Google'd my a** off and still can not find a definitive answer
to this question:

Does anyone out there have experience with P4BGL-MX/533?

Can I use a 533 FSB Celeron to replace a dead 400 FSB Celeron on the

(It's my kids homeowrk computer not the hotshot game playing machine...
Obviously I'm being shamelessly cheap here in my search for a

(ASUS support fails to mention Celeron 533 as supported.)

Any help would greatly appreciated.


Re: Replace 400 FSB CPU w/ 533 FSB CPU wrote:

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Start with the Asus CPUSupport web page. I looked up your mobo and
it is here:

The common theme, on all but a few of the processors listed, is they
are the "Northwood" family. You are being seduced by "Prescott"
family processors, and if you buy one of those and plug it in,
you'll be rewarded with a black screen and no starting beep.

Willemette = 0.18 micron, 1.75 volt, mostly S423 packages, old, old, old.
Northwood  = 0.13 micron, 1.5  volt, more S478 (what you got)
             Comes as P4 with 512KB cache, and Celeron 128KB cache
Prescott   = 90nm (0.090 micron), 1.2-1.4V, S478/LGA775
             Comes as P4 with 1MB cache, and Celeron D 256KB cache
             These don't work in your motherboard.
(there are now 65nm processors but we'll ignore them)

So you cannot shop for "Celeron D", you may only shop for

I looked on Pricewatch, and by using the search terms 478 and
0.13, got a page of processors to buy. Not all the processors
on this list are exactly the right type (the FSB800 one would
work, but it would run slower than its rating if plugged into
your board).

There are a couple of Celerons for sale. $37 and $44 at,
for a 2GHz and a 2.4GHz model. I'm including the link to the
2.4GHz one -  it is OEM, meaning no heatsink/fan comes with it,
and you can reuse the heatsink/fan from the dead one:

If you were a rich guy, the fastest processor that will fit
in that board, is here:

In the upper right hand corner, is a 2.8GHz/FSB533/512KB cache
Northwood, for $200.

Ebay might be another place to find dirt cheap processors,
and for the stuff you are interested in, perhaps they won't
have been tortured by the overclockers. But if the Ewiz offers
are on the level, I think you have your solution right there.


Re: Replace 400 FSB CPU w/ 533 FSB CPU

Many thanks, Paul. You confirmed what I had suspected  based on the
ASUS CPU support info. My hope was that maybe, despite ASUS support
claims, some people may have additonal info about using newer CPU's in
older M/B's.

Thanks for the retail links. I had checked eBay but was wary of what
shape a CPU might be in considering the OC'ing it may have been
through. I had not been aware of the ewiz site. I had checked into
PowerLeap. $$...

Cheers and many, many, thanks.

Paul wrote:
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Re: Replace 400 FSB CPU w/ 533 FSB CPU wrote:

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There are two issues with any processor upgrade. Does the
BIOS support it (recognition) ? And is it socket compatible ?

Initially, the belief was, when Celeron D first came out,
that you could just pull a Celeron and place a Celeron D in
its place. After seeing several postings from people who had
tried it, the results were always the same - black screen
and no beep.

I downloaded the datasheet for the Celeron D, and Intel
changed one pin on the bottom of the processor. The processor
uses that pin as a sensor. If the processor detects, I think
it was a ground signal, the processor knows it is not suppose
to start, so it doesn't even try to run any instructions.
In other words, Intel made that pin into a "Prescott Ready"
motherboard detector.

In theory, you could cut that one pin off the processor, and
prevent the processor from detecting your motherboard type.
That is not exactly a warranty friendly approach.

Now, the manufacturers know about that little detail, and there
is no sense adding BIOS support, for a processor that needs a
pin cut off.

So the support issue should be pretty "cut and dried". It is
not a matter of "trying harder" or "wiggling it a little bit" :-)


Re: Replace 400 FSB CPU w/ 533 FSB CPU

<> Can I use a 533 FSB Celeron to replace a dead 400 FSB Celeron ...

Are you sure the CPU is the problem? A CPU failure is extreemly rare.
Motherboard or power supplies fail all the time. Be sure to test with known
good system.

Re: Replace 400 FSB CPU w/ 533 FSB CPU

HI Kent,

Sorry for the delay. Thanks for the reply.

Yes. I am sure the CPU is fried. CPU cooling fan bearings went and CPU
went up in smoke. I had heard it "chirping" for a few days. The mobo
looks ok. I took Paul's advice and bought a replacement from ewiz. I am
awaiting the replacement.

My previous experience when this happens is the mobo is ok, and indeed,
the mobo *appears* to be fine. We'll see. If not keep an eye  out on for my ad! ;-)

Obviously, a new mobo/cpu/ram combo is the preferred solution but then
I'm out $150 rather than $35. Right now, cheap is better than good.
Like I said, it's the kids homework PC: wikipedia, google,  ms word
(uggh! i wish they'd use ooffice!), etc.


Kent_Diego wrote:
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Re: Replace 400 FSB CPU w/ 533 FSB CPU

Ahh, on second thought, you raise an excellent point: I've only had
early generation AMD CPU's (i.e Duron's) die because of overheat.

I always thought the Intels were better protected. And you're right,
CPU failure is uncommon. Even if you put the thing in the wrong way,
they usually survive.

(I am certainly guilty of recently tweaking the thing. Maybe I got a
vcore set the wrong way. Hmmm...)

Regardless, I am taking your advice and double-checking...


Kent_Diego wrote:
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Re: Replace 400 FSB CPU w/ 533 FSB CPU wrote:
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So what's the story Tom?

I've only just checked the group and seen the thread. It's really rare for a
CPU to pack up, especially an Intel one. (I'm an AMD man, you wouldn't think
it huh?).

I'm thinking it's no good getting a replacement CPU, installing it, then
having *it* fry. Maybe the overheating wasn't limited to the CPU proper and
caused damage to the mobo? I hope not, just know that, other than
'mechanical' or over-voltage damage, most modern-ish CPU's are

Re: Replace 400 FSB CPU w/ 533 FSB CPU

Yes, i totally misdiagnosed this one.
(said a-very-red-in-the-face-usenet-poster)

It appears it might be a malfunctioning mobo (but still some signs it
could be a trivial ps problem.) When I originally took the case cover
off, I mistook the inoperative cpu fan (and it's recent chirping) as an
indicator that the cpu overheated,  and coupled with the memory of an
AMD Duron which fried when the cpu fan quit, i jumped to conclusions

Kent's point about CPU survivability got me rethinking about CPU
thermal protection, indestructability, etc.

The ps voltage seems ok when it's installed in another system and
checked with voltmeter, but nothing will power up on the problem mobo
and there's no voltage across the filter caps.

Maybe the problem mobo current draw is heavier and pulls the voltage
down? Maybe a voltage regulator? Short in the mobo somewhere? Maybe a
short in a ram module? I was fiddling with vcore's a few months back
but i would think it would've fried then rather than later. (I'm not an
aggressive overclock'er; more of homebuilder tweaker.). Still might be
a ps issue.

My wife is telling me to "Just build a new one and quit messing with
it." So *I think* I've got the green light for a replacement. Besides,
this board was never something to be impressed with even when it was
new. Luckily, I was able to RMA the replacement cpu (thanks to a quick
phone call inspired by ACHO) since I hadn't received yet.

Sorry to waste bandiwdth and electrons with this problem. Posting to
this group for this dated system is like posting to
and asking how to fix the transmision on a pickup truck..

(But if you want a good answer, this is the place)

Thanks again,

~misfit~ wrote:
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Re: Replace 400 FSB CPU w/ 533 FSB CPU wrote:
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Thanks for the update Tom.

Most-times, mobo problems from having a higher vcore don't show immediately.
They occur over time when running out-of-spec starts to take it's toll on
the on-board power circuitry (MOSFETs, capacitors....) that wasn't designed
to do what it's doing. The economics of modern computer components don't
allow most manufacturers to have 'margins' in their circuit design. They're
built to a price-point.

This I know as I was running Tualatins in a board designed for mostly
Medicinos but with support for the, then new, Coppermines. The components on
the board failed after several months. I just happened to have a couple more
identical boards and checked them out running the same configuration and
found some *extremely* hot MOSFETs when running under load. A small fan,
hot-glued into a position where it blows directly onto the components, in
each case, fixed the problem. I still have two of those boards running now,
years later, running at 1.4GHz with Tualatins. I check the MOSFET cooling
fans frequently, they are more critical to the machine's life-time than the
CPU fan.

Oh, and don't worry about posting here about older systems like that. I'm
full of first-hand experience with OCing Coppermine/Tualatin Celerons and
other, ancient technology. I'm more than happy to share it. ;-) Those were
the days when OCing was an esoteric art, frowned upon by component
manufacturers and most computer system builers alike. These days mobos and
CPUs are sold as OC-friendly, often printed right there on the box. It's
mainstream stuff now and far less interesting. ;-)

Have fun with your new PC. :-)

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