rec.autos.simulators

Jason, the standard Intel fan will be okay if your internal case
temp is not too high.  If you don't have a motherboard with a
built-in temp sensor, I'd highly recommend a $15 indoor/outdoor
digital thermometer -- stick the probe inside the case, out of
direct airflow.  Less than 100F is 'cool' <g>.  The Intel fan is
okay but it is limited to the ambient temp inside the case (as is
any CPU fan).

Also, I hear that it is good to run the Celeron at the stock
speed for a few days before bumping up the clock speed.
Difficult to define technically, but probably can't hurt.

I had to bump my core voltage up to 2.2v to get my C300A stable
at 450... so that, plus a Banshee card (HOT) and a TNT card
(warm) plus several other cards means that I have several case
fans to keep the internal case temp down to 95F (as measured by
the Abit BH6 mobo temp sensor).

Guys, please fill me in here...
If the C300A Celeron (128K cache, right?) is so easy to overclock to 450
(with a 100MHz motherboard, right?), is there any point at all in getting a
C333A since that costs 30 percent more in the UK?

And what's all this about 2.0v and 2.2v core voltage? What does that refer
to and how do you set it?

If the C300A really is as good as it sounds, I would quite happily go for
one and just overclock it at times when I need it, like playing GPL.

Cheers, Gwyn.

No problem, I'll buy the CPU direct in Malaysia - I live there.

Jens

---------------------------------------------

Remove "NOSPAM" before using my email-address

It's not the Celeron 300A's that have been made non-overclockable to
450, but rather, it is certain of the newer PII-300's, due to Intel
using slower cache chips on them (so they don't work at 100 MHz FSB).
The Celeron 300A has the cache on the same die as the cpu, so it runs
at the same speed as the cpu, but the PII-300 (even the newer ones
that work at 2.0V) have the cache on separate chips soldered to the
processor circuit board and running at one-half the cpu speed.

The Celeron 300A's remain good overclocking candidates, but even so,
some people have been unable to run them at 450 using a 100MHz FSB.
Also, many people have reported that it was necessary to increase the
cpu core voltage above the rated 2.0V in order to get the C300A to run
stably at 450, and because of this the Abit mainboards are favored as
they have a soft menu and don't require jumpers for setting the cpu
core voltage.

BTW, the Malaysian-made C300A's seem to be pretty highly favored for
overclocking. Good luck if you try one.

See http://bxboards.pair.com for some more info.
---

=============
To e-mail me, kindly delete *hippo* from my address.
Spammers: meet the Hippo at Newsguy (Super Zippo).

Lucky guy. I really like Malaysia, from the nice shops in the centre
out to places like Am Pang Park, you can find anything you want to
buy. One of the best places in the world to find durian as well :-)

It's a few months now since I've been there but I always enjoy a
visit.

Cheers!
John

The Celery 333A is not as overclockable as its multiplier is locked at
5.0x, and doing 500MHz with these CPU's is pushing it.  The 300A at 4.5x
is much more "doable".

The CPU's core voltage.  Most new motherboards autodetect it for
whatever the default for the CPU is (ex. 2.8v for the older 0.35 micron
Klamath Pentium II's, 2.0v for the newer 0.25 micron Deschutes Pentium
II's and Celerons).  But with an Abit BH6 motherboard, you can override
this and set the voltage manually within the BIOS setup, which
oftentimes will help an overclocked CPU become more stable.  But the
tradeoff is more heat generated, so be sure to have adequate cooling.

No, don't do it. Just buy a 300A (yes, the "A" denotes the cpu has
128kb on cpu cache) I have a 333A and despite several unsuccessful
attempts it will only reliably o/c to 375 (5 x 75) I have had it
running at 415 (5 x 83) but not reliably, 500 (5 x 100) did not work
at all.

The 333A is locked at a multiplier of 5. So if you try to overclock
it, you have to mulitiply the busspeed by 5 which is pushing the cpu
and the busspeed to its limits before you even start o/c'ing? So the
only options are as above 375, 415, or 500. 375 appears to work fine,
415 works but not reliably and 500 not at all, as you are trying to
push the cpu that little bit too far?

The 300A on the other hand, is locked at a multiplier of 4.5 which is
much more user friendly. The options are now 300 (66 x 4.5) 337 (4.5
x 75) 375 (4.5 x 83) 450 (4.5 x 100) or even 504 (4.5 x 112) Most
people attain 450, some manage 504 (though how reliable they are at
that speed is debateable?)

Your m/b sets the core voltage, (the voltage used to power the cpu)
most newer bx m/bs have a core voltage around 2v. But when you try to
o/c a cpu, it sometimes needs more voltage to attain the extra speed,
so people try raising the voltage until the cpu performs reliably
(2.2v appears to be a reliable setting to try?).

Most m/b's allow you to change the core voltage via jumper settings
on the m/b or via a *softbios* menu (eg:- the Abit BH6 & BX6 m/b's)

GPL.

You can do this easily if you have a m/b that allows softbios  
settings, you merely boot up the pc, go into the bios, and set the
cpu/voltage settings, then let the pc carry on booting, and away you
go.

But, if you have a m/b that requires jumper setting to be changed,
you have to take off the case, alter the m/b jumpers, start the pc,
etc, etc, this is too much hassle for most people unles you are gonna
leave the pc o/c'ed all the time.

Also bear in mind the o/c'ing (especially increasing core voltages)
results in increase heat build up, and you need to check the internal
case temperatures or buy extra fans to cool the m/b & cpu.

There *are* risks to o/c'ing, you *can* damage your cpu! Its up to
you?

8-)

*Peter*   #:-)

[This followup was posted to rec.autos.simulators and a copy was sent to
the cited author.]

No, do not buy the 333A.  It is set to a 5x clock multiplier and it is rare
that it successfully o/c to 500Mhz (100Mhz bus x 5).  For an excellent
explanation of how to effectively o/c go to CPU central's O/C FAQ:
http://www.cpu-central.com/celeron-oc-faq.html

Some MB's (namely Abit's BH6 MB - IMHO this is the ONLY MB to buy) allow
you to change the CPU voltage.  The default is 2.0v, but when o/c it is
sometimes necessary to up the voltage (Never a good idea to go beyond
like 2.3 or 2.4) to have the CPU run effectively and stable.

I have been running a o/c C300A (450) and it is AWESOME.  I also LOVE GPL
and it has been great to play it on this system.

Good luck,

--
Rob

Just an addition:

Depending on the jumper layout and the case you have, you sometimes
can use the unused turbo switch (do ATX cases still have them?) to
switch between two front side bus speeds. My old board required
changing one jumper from 1-2 to 2-3 to go from 66 to 75MHz, and I did
just that.

One could even add some more switches to the case and configure all
the settings from the outside; but flicking all those switches prior
to boot is something that only ***-flightsimmers would dig. :)

Anyway, in my experience, it's not worth the trouble to go back and
forth between clock speeds: find a reliable and fast setting and stick
to it. You have to shut down the machine to change the speed. So if
you choose the wrong speed for your task, you have to shut down
Windows and reboot, or use the "wrong" settings. But, every time you
use a different speed with a game that uses the joystick, you have to
recalibrate your joystick...

There's a neat little tool I'd like to recommend to all overclockers:
CPUIdle by Andreas Goetz. It runs a HLT command in Win9x which tells
the CPU to "actively" do nothing when it's not used, instead of idling
at full speed, heating up and doing nothing. This won't help you when
running GPL or some other CPU hungry app, but it keeps the CPU cooler
when running less demanding programs (such as e-mail programs or
newsreaders, f.i.) Thus, you achieve the same result you would have
when you clocked up and down the CPU according to usage. CPUIdle can
be found at www.stud.uni-hannover.de/~goetz.

--
Wolfgang Preiss   \ E-mail copies of replies to this posting are welcome.