Celeron 100Mhz

Are Celerons in line to become the next overclocking wonderchip now that Intel has introduced it in 100Mhz flavor?

Uhhh, no.

Building A New System?

Unless you (or the person you are building for) has an Intel fixation, don’t even think about using a Celeron in a new machine if you’re at all concerned about performance.

Why? The Duron is clearly better. Take a look here. The Duron pretty much wallops the Celeron.

If you’re building a system so Aunt Emma can browse the web, and you’re a little uneasy about Via-based motherboards, then once the 100Mhz Celerons become reasonably priced, then this would be a better idea than the 66Mhz versions. Not until then.

Upgrading A Current System

There’s a much stronger case for the Celeron being used as the last processor upgrade for an older system. Even though the Celeron is more expensive than the Duron, it’s cheaper than a Duron + motherboard, and has been a very cost-effective move for many people.

“Has been?” Two issues cloud the new Celerons’ future even as an upgrade chip.

The cC0 Split Plane Issue

There’s been some comments that the cC0 Celeron will not boot with BX boards. Paul Panhorst pointed out this item for one of Intel’s spec sheets. “Vcc core voltage 1.70V/Requires a motherboard with a split plane for the Vcc”

He goes on:

Having never heard anything about “split plane”, I called Intel this
morning to inquire. Their reply was that a “split plane” is part of the
i810e and higher chipsets (815,820,840). Therefore the cC0 is only usable
with these sets. They did not know whether the VIA 133 set supports it,
and the BX definitely DOES NOT.

Is this true? Hard to say. Some have reported that their BX board will not boot with a cC0 Celeron. Others have had no problems.

To protect yourself, you shouldn’t buy one of these things until:

  • The manufacturer’s website indicates that your motherboard supports the CPU and
  • Check Deja and type in something like “cC0 {your motherboard} and see if someone’s gotten the combo working.

    Other 100Mhz upgrade blues

    The following is aimed at those of you who are “cheap”. By “cheap,” I mean you will not or cannot lay out money to upgrade other parts of the system just so you can run at 133Mhz or better in an overclock.

    Those who try to overclock a 100Mhz Celeron on an older BX board will run into exactly the same problems those who tried to overclock a Coppermine almost a year ago ran into.

    Look at our database for the early Coppermine processors. Again, and again, and again during the early Coppermine era, you’ll see entries of people bought the processor, then found themselves have to spend more upgrading other components (usually memory) to get the machine to run at 133Mhz.

    This defeats the purpose of the whole exercise, which is to get a cheap upgrade.

    In contrast, if you buy a Celeron 66Mhz processor for a system that’s already running at 100Mhz, the rest of your system will be doing just what it’s doing now.

    Do you lose out on performance? Sure, about . . . 3-5%. If you won’t or can’t replace your RAM to get that 3-5% should that prove necessary, play it safe and stick with a 66Mhz.


    Let’s face it, Celeron owners tend to be . . . frugal. At the time you bought your system, the odds are you didn’t lay out big dough for items like memory. You probably bought PC100 RAM as cheaply as possible, and it’s worked well enough.

    Don’t assume your PC100 is going to work at 133Mhz or better. If you bought generic PC100 RAM at the time, it probably won’t. If you bought PC66 memory that manages 100Mhz; expecting 133Mhz out of it isn’t expecting results, it’s expecting miracles. If you happened to buy very high quality PC100 RAM at a premium price, you’ve got a pretty good shot at 133Mhz, but no guarantee.

    CPU Capability

    Running an 800Mhz Celeron at 133Mhz would get you 1067Mhz. After taking a quick look at our CPU database, the odds on getting 1067Mhz or more doing that are about: 2%. Even if you adjust for different steppings, the odds on hitting that speed are really against you.

    PCI Blues

    OK, you’ll settle for 1Ghz. Now you have to be concerned about PCI speed. When you run above 100Mhz on a BX board, especially an older one, you are also overclocking the speed of your hard drives and PCI devices. They tend not to like that, especially when you overclock them more than 15%. What you need to find out is whether or not your motherboard will let you:

  • Run at 125Mhz or better (if it’s an older board, good chance the only available speed around that is 124Mhz and
  • Whether or not your motherboard will let you run a PCI divisor of /4 at your chosen speed.

    If you can’t answer “Yes” to these two questions, then don’t do it. If you don’t know or don’t want to find out, then don’t do it, because if you do it, and the answers aren’t “Yes,” you’ve got a 50% or greater chance of failing. Up to you.

    If you can’t risk failure, it is much safer to buy a 66Mhz processor like the 566 or 600, get an almost certain 850-900Mhz, then move on from there. The odds on you hitting 1Ghz with a 600/66 are probably a lot better than doing it with an 800/100 on an older BX board.


    By raising the FSB over 100Mhz, you are also overclocking the AGP transfer ratio. This has proven to be a problem with perhaps 10% of the video cards out there. This probably won’t be a problem, but it could be.


    Current Celeron overclockers have been cashing in on safe bets with the 66Mhz chips. Those who bought a 566 or 600 chip practically guaranteed themselves a nice stable system at 850-900Mhz, and some got a good deal more than that at relatively little risk to their older systems.

    Going to 100Mhz greatly increases the risks involved in overclocking for very little additional reward.

    If you do this for the adventure, and can afford failure, go for it. This piece wasn’t written for you.

    It’s for those people who want or need to make their computer investment last, and who can’t afford to replace components that this is meant for. If that’s your situation, stick with the older Celerons. You’re much safer.

    Email Ed

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