rec.autos.simulators

Intel Celeron processors are processors designed by Intel for the basic
PC.
In comparison to their Pentium II counterparts they can be considerably
cheaper and for a lot of PC users, especially game players, offer an
unrivalled price/performance ratio.

The main difference between the Celeron processor and the Pentium II is
that Celerons have less or no Level 2 Cache. Level 2 cache is important
for business applications and computer graphics design, which means that
Celerons may not be suitable for graphic design artists and people who
use intensive applications.

However, for games players Level 2 Cache is relatively unimportant as
games tend not to utilise this too heavily. Celerons have now become the
natural choice of gamers because not only do they offer a great
price/performance ratio but can be substantially overclocked too. (More
on this later)
General Questions | Technical Questions | Celeron Overclocking | Analysis
and Conclusion

General Questions:

Q: How many different types of Celeron processor are there?
A: Currently Celeron 266, Celeron 300, Celeron 300A and Celeron 333A.

Q: What is the difference between these four processors?
A: The Celeron 266 and 300 are processors using the standard Pentium II
design but without Level 2 Cache. The Celeron 300A and 333 have 128k of
Level 2 Cache.
This is the main difference.

Q: How much should I expect to pay for them?
A: Celeron 266: $70, Celeron 300: $100, Celeron 300A: $170, Celeron 333:
$220
The above prices are approximate and vary from retailer to retailer.

Q: What is the life span of a Celeron processor?
A: Typically, processors are designed to last for a minimum of 10 years.

Q: What motherboards can accept the Celeron processor?
A: Any Intel Pentium II Slot 1 motherboards, using the LX, EX or BX
chipset.

Q: How much slower are Celerons compared to Pentium IIs?
A: The Celeron 266 and 300 perform like a Pentium II 233 and Pentium II
266 respectively for games, whereas the Celeron 300A and 333 perform
identically to their Pentium II counterparts. For business applications,
the 266 and 300 perform at around the 200-233mmx level.

Q: The stores I called all say that Celerons are rubbish. Why is this?
A: Retailers generally are not aware of technicalities. Celeron
processors can be run safely much faster than they are labelled. Once you
have increased their speed (overclocked) you will see huge performance
gains.

Technical Questions:

Q: What percentage impact on performance does removing Level 2 Cache
have?
A: This is difficult to answer as performance can vary from application
to application but as a guide I would estimate a 5-10% performance
decrease in games and possibly as high as 20-30% in business
applications.

Q: How effective is the 128K of Level 2 Cache on the 300A and 333A
processors?
A: Extremely effective. The Level 2 Cache on the 300A and 333 processors
is running at full cpu speed. On Pentium II processors the cache usually
runs at only half of the cpu speed. The doubling of the cache speed
counteracts the reduction in the physical amount of cache and hence
produces virtually identical performance to a true Pentium II.

Q: What is the technical name for a Celeron processor?
A: The core is known as Mendocino and is currently Family 6, Model 6,
Stepping 0 for all 300A and 333 Celerons. Celeron 266 and 300 processors
are produced using the Deschutes core which Pentium II 333, 350, 400,
450mhz processors use. Celeron 266 and 300 can be Family 6, Model 5,
Stepping 0, 1 or 2.

Q: What is OEM and what is Retail?
A: OEM are processors that are sold unboxed and usually in bulk to
retailers and large companies who then put them in their PCs which are
sold to consumers.
Retail processors are in sealed Intel boxes and are sold individually to
the public and generally come with a heatsink and fan already attached.

Q: Why are retail processors more expensive than OEM?
A: The price difference arises due to the extra cost of packing each cpu
individually, in addition to the cost of providing a heatsink and fan.

Q: What are the correct bus speed and multiplier settings for my Celeron?
A: All Celerons at default run on a 66mhz bus speed. The multiplier
should be set to 4x for 266, 4.5x for 300 and 5x for 333mhz processors.

Q: How do I fit the Celeron into the Slot 1 connector?
A: Retail Celeron processors will come with a black installation bracket
which you screw into the motherboard before seating the cpu. OEM cpus may
be supplied with this device but only at the discretion of the retailer.
According to Intel you are in violation of your warranty if you do not
use the correct installation bracket. (How the hell could they know
anyway?) ;-) lol

Q: Which Celeron do you recommend and why?
A: If you intend to run your Celeron at its proper speed then I would
recommend the 300A. If you are willing to become an overclocker and run
your processor faster than it is labelled then a 266 or a 300A would be
your best option.

Q: Which Celeron do you own personally?
A: I run a Celeron 266 at 448mhz.

Celeron Overclocking:

Overclocking, what on earth is it?

Now we finally descend onto the juicy stuff. This section will explain to
you why Celerons are worthwhile and just what it is that turns normal
people into dedicated enthusiasts. Overclocking is an art and is an
incredibly satisfying pursuit. Read on to discover exactly what
Overclocking is and just how it can benefit you and your PC.

Overclocking is the art of running your processor faster than was
intended by Intel. This is achieved by changing the bus speed and
multiplier settings on your motherboard.
Typically, any Intel processor can be overclocked and this usually arises
due to the fact that Intel produce the highest quality processors and
before selling them ensure that they are stable at speeds higher than
they are labelled as.

For example: A Pentium II 400mhz processor may be tested to be stable at
466mhz for it to pass Intel's quality control tests. This ensures that
when you run the processor at 400mhz you will not encounter any problems.

Overclocking in a nutshell, is pushing the cpu to see how far it will go
before becoming unstable. Once you have discovered the speed at which it
becomes unstable you then know how fast you can safely run it at.

Overclocking General Questions:

Q: How do I overclock a Celeron?
A: All Celerons are "Multiplier Locked" or "Clock Locked". This means
that you can not change the multiplier setting on your motherboard. To
overclock you must increase bus speed.

Q: How do I increase the bus speed?
A: Depending on your type of Motherboard you can alter the bus speed
either by changing the cpu settings in the bios or by reconfiguring
jumpers on the actual motherboard itself. Consult your Motherboard manual
for further details.

Q: What can I change the bus speed to?
A: Bus speed is always set at 66mhz by default. Your options for
increasing can be some or all of the following depending on your
motherboard type.
66mhz + turbo, 75mhz, 83mhz, 100mhz, 100mhz + turbo, 112mhz, 124mhz,
133mhz.

Q: What is turbo?
A: A function which boosts the speed of your system by 3%.

Q: OK, so I have a Celeron 266. How far can I overclock?
A: 496mhz is the current record for a stable Celeron 266. This cpu is
guaranteed to make 333mhz, almost guaranteed to make 400mhz, a reasonable
chance of 448mhz and a very small chance of 496mhz.

Q: OK, so I have a Celeron 300. How far can I overclock?
A: 464mhz is the current record for a Celeron 300. This cpu is guaranteed
to make 338mhz, Virtually guaranteed to get 374mhz, and has reasonable
chances at 450mhz or 464mhz.

Q: OK, so I have a Celeron 300A. How far can I overclock?
A: 374mhz guaranteed. 450mhz about 80-90% of the time. 504mhz about 20%.

Q: OK, so I have a Celeron 333. How far can I overclock?
A: 375 guaranteed. 415 almost guaranteed. 500mhz about 20-25%.

Overclocking technical questions by category:

1) Motherboard issues
2) RAM issues
3) PCI devices issues
4) CPU issues

1) Motherboard issues

Q: How good is the Asus P2B for Celeron overclocking?
A: The motherboard itself is excellent, extremely stable and reliable.
However, you do not have the option of increasing voltage and can only do
so by taping pins.

Q: How good are Abit motherboards?
A: I personally recommend Abit. The BX6 series is superb. Cpu speed can
be adjusted in the BIOS and so can voltage and all other settings. This
is great for overclockers.
The BH6 improves on the design of the BX6 by adding support for 124mhz
bus speeds.

Q: What's the difference between the EX, LX and BX chipsets?
A: EX is terrible. Avoid this at all costs. It only supports 66mhz bus
speeds. LX only supports 66mhzBX is the King and supports 66 and 100. LX
and EX boards will (sometimes) have 75 and 83 MHz FSB settings, BX will
sometimes have 75, 83, 103, 112, 124 and 133. Anything but 66 on the
EX/LX, and 66/100MHz on the BX. EX boards, however, tend to not cost much
less than their LX or (even better) BX counterparts, and have an
extremely small amount of slots. (Question/Answer edited by Editor Guy)

Q: I have overclocked but am unstable. Help!
A: Set speed error hold in the BIOS to disabled if your motherboard has
this function.

2) RAM issues:

Q: Is any SDRAM good for 100mhz bus speeds and above?
A: Generally yes, but not necessarily. SDRAM rated at 12ns will not be
stable on a bus sped of 100mhz. Anything 10ns will be OK at 100mhz with
CAS 3 selected in the BIOS and not CAS 2.
Anything 8ns will be fine at 124mhz bus and below at CAS3.
Premium 8ns SDRAM rated for CAS2 will work on 133mhz bus speed at CAS3.

Q: What is CAS?
A: CAS is "Column Address Strobe" and is the number of PCI bus ...

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Contents:

Introduction and Disclaimer
So you want to overclock a Celeron?
Why is the Celeron so overclockable?
What does stepping mean?
What is an S-code?
What is 'multiplier locking' and 'bus locking'?
Which type of Celeron should I buy?
Which motherboard should I use?
What kind and how much memory?
What about cooling?
How do I overclock?
What if it doesn't work?
Will it damage my CPU or other components?
Where can I learn more?

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Introduction and Disclaimer
I created this FAQ because, after reading literally thousands of posts, I
still see the same requests for basic instructions over and over in each
Newsgroup and forum.  There are many web sites with similar information,  
but many people either can't find these sites or they don't have web
access.  Since I have never seen a FAQ like this posted in any of the
Newsgroups I read, I took it upon myself to offer this small contribution
to novice overclockers everywhere.  I don't claim to have all the answers
and I can't guarantee that everyone will be able to overclock their
Celeron, but after reading this FAQ you should be well on your way to a
successful experience.

Overclocking is not recommended by any manufacture (especially Intel) and
will void your warranty.  I do not advise anyone to follow these
instructions unless they are willing to assume all associated risks.  I
have consolidated in this document information that I've learned while
overclocking my own system or that I have read about the experiences of
others.  Overclocking can damage your system.  Working inside your power
supply or wiring 110 volt fans can cause serious personal injury if done
by the inexperienced or without the proper precautions.  If you're unsure
or in doubt about any of these procedures, seek professional advice.  I
am providing this document for informational purposes only.

If any one out there in Net-land has suggestions, comments or
contributions for this FAQ, feel free to contact me.  Frank Monroe  
email: monroef...@hawaii.rr.com

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So you want to overclock a Celeron?

You've read a few posts, maybe visited a few web sites.  Everyone is
reporting their success and claiming fantastic speeds from a lowly 266 or
300 mHz CPU.  You're excited at the prospect of a high performance CPU
for, essentially, small change and you want to get in on the action.  The
speed of a P2-400 or -450 for $90 or $150 sounds too good to be true.  
But wait, they're talking about S-codes, multiplier locking, Pin B21,
CAS-2, and other esoteric terms.  Names like Deschutes, Klamath and
Mendocino are bandied about while you wonder what these words have to do
with computers.  Now you're confused.  How hard is this going to be?  Is
it worth it?   Do you need to be an Electrical Engineer to overclock a
Celeron?  In a word, no.  With the right hardware and a little luck, it
should be a snap.

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Why is the Celeron so overclockable?

As you may know, a given chip design is used for CPU's of many different
speeds.  The P2 and Celeron designs are named after Western US counties:
Deschutes, Klamath and Mendocino.  More on this later.
In theory, a CPU is tested first at it's maximum speed.  The ones that
pass the testing process at this speed are marked as such and sold as
top-of-the-line CPU's.  Those that fail at the fastest speed are tested
at successively lower and lower speeds until they run reliably.  These
slower cores are then marked with the speed at which they passed the
testing process and sold as slower processors.  At least, that's the
theory.  No one really knows how Intel decides which cores get marked for
a given speed.  Several other factors, such as customer demand and
production quality, affect how many processors of each speed are
produced.

A CPU of any given speed can usually be made to run somewhat faster if
one is willing to play around with the motherboard settings. This is the
overclocker's bread and butter.  Now, through a convenient turn of
events, Intel has produced a CPU with an unusually high capacity for
overclocking.

Intel has long controlled the high-end CPU market while it's competitors,
Cyrix and AMD were gaining market share in the low- and mid-price range
because of the popularity of lower priced PC's.  Intel finally realized
what was happening and wanted to recover the low ground while also
keeping the high end market (can you say "total market domination"?).  
When Intel designed the CPU core for their newest line of processors, the
P2, they changed the way the CPU was mounted.  All P2's are mounted on a
circuit board, called an SECC (Single Edge Contact Cartridge), that plugs
into a special, patented CPU slot (Slot 1) similar to a PCI slot.  
[Intel calls the Celeron packaging a SEPP (Single Edge Processor Package)
but it's still compatible with the Slot 1 connector, go figure.]   AMD
and Cyrix do not have a Slot 1 CPU, so if you want high-end speed, you
need to buy an Intel processor.   Thus the high-end market is preserved
for Intel.  Now, Intel needed a cheap Slot 1 CPU to corner the low-cost
PC market.

Enter the Celeron line. To reduce production costs, Intel left out the
expensive Level 2 cache.  Also, to eliminate design costs, the original
Celerons (C266 and C300) used the same CPU core as the new 350-450 mHz
P2's (code name Deschutes).  [Remember, design costs account for a huge
percentage of the total cost of a CPU.  Once in production, it costs
exactly the same to manufacture a core destined for use as a 266 mHz
processor as it does to use that same core in a 450 mHz processor.]  Many
media pundits immediately dubbed the Celeron a backward-stepping piece of
crap because of the lack of the L2 cache.  Later, perhaps due to the poor
reviews from hardware critics, Intel released the Celeron 300A and 333
with 128 Kb of built-in cache. Again, they used basically the same core
design with some modifications to incorporate the on-die cache.  The
C300A and the C333 modified Deschutes core carries the code name
Mendocino.    Since Celerons use a Slot 1 motherboard, you can't upgrade
to one of Cyrix's or AMD's fast new CPU's later, when prices come down.  
They don't have Slot 1 CPU's and Intel has the patent.  Now Intel has
again regained a foothold in the below-$1000 PC market and insured that
the upgrade dollars also come home to Papa Intel too.

Here's where it gets interesting.  The fastest P2 CPU's (350 to 450)
require a relatively new type of Slot 1 motherboard with the BX chipset.  
The BX motherboard runs at a bus speed of 100 mHz.  They can also run at
66 mHz bus which allows them to accept slower P2 CPU's (233, 266, 300 and
333) and Celerons. The Celerons are supposed to be used on the earlier EX
and LX generation of Slot 1 motherboards which run at 66 mHz only.  Since
the Celerons have the exact same core as the new architecture P2 CPU's,  
there's nothing to stop you from setting the bus to 100 mHz and running a
Celeron at 400 or 450 mHz.

People started buying BX motherboards and Celerons and overclocking the
hell out of them by setting the bus speed to 100 mHz. A chip meant to run
at 266 running at 400 mHz and more was unheard of previously.  It's all
because Intel is trying to capture the low-cost CPU market without the R
& D costs of a new chip.  It's really a marketing stroke of genius when
you think about it.  Produce one type of CPU.  Take the best ones, add
512 kb of fast, expensive cache and sell it as the top-of-the-line CPU
for $700+.   Take the rejects, leave off the expensive L2 cache and sell
them as cheap Celerons.  Except they're too smart for their own britches.  
The production yield of 450 mHz cores is too good and the "rejects" are
too few and far between.  Because they want to flood the market with $100
CPU's, they have to mark them as 266 to 333 mHz Celerons and sell them
cheap anyway.  It doesn't cost them any more since both chips came off
the same production line.  Because the P2-450 market is relatively small
compared to the low- and mid priced market, the demand is greater for
Celerons.

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What does stepping mean?

Celerons come in four flavors.  The C266 and C300 without L2 cache and
the C300A and C333 with 128 Kb L2 cache.  Each type of Celeron has
several slightly different variations, called a "stepping".  Stepping 0
(zero) cores are the original production run.  When minor imperfections
(bugs) are found in the instruction programming (micro-code) of the core
or in other parameters of the chip, they are fixed and the next batch of
cores will incorporate the changes.  This batch will be identified as
stepping 1.  If another change is required later, the stepping number
will be incremented again.   As each successive refinement to the chip is
made, the next higher stepping number will be assigned.  For many
reasons, one stepping may be easier to overclock than another, but
usually the higher stepping cores make the best, most stable CPU's.

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What is an S-code?

An S-code (Intel actually calls it an S-Spec.) is a 5 character
designation beginning with 'S' used to identify the various different
types, stepping, voltage and packaging of Celerons and other Intel
processors.  There are currently 14 (as of  27 Sep 98) different S-codes
for the Celeron family of CPU's.  OEM packaging is just the SEPP in  a
plastic container.  There is no heatsink/fan attached, so you need to buy
your own.  The warranty, if
...

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