Pentium and Celeron: what's the difference?

[Declan_Vee]

While we're on the topic. How do the 64bit CPUs differ?

If you're doing 32-bit calculations, they're just more expensive.

Well that's one way of telling it like it is. Cheers.

I'm running an Athlon 3200, so no need to preech to the coverted or anything, k.

[Apeotheosis]

thats why i chose an athlon xp 2800+

Athlon for life!

[Chao]

I've actually heard the same thing. It may be the case, which makes Celerons excellent for overclocking. What I heard is that Celerons are Pentiums that don't quite meet spec, so they're downclocked to a Celeron spec that they do meet, and sold then. Some people undo this, and use the full potential of the chip (whatever the full potential of a Celeron may be).

Nope, there are other differences (mainly that they have half the cache, for some applications there is little noticable difference, but anything involving heavy calculations on very large files will notice a significant hit, eg video editing).

What you're thinking of is the clock speed. When a chip is made it is tested at different clock speeds. Depending on various factors different chips will not be able to sustain the same clock speed as others in the same batch and remain stable. So they set the chip to the speed at which it remains stable, lock it and ship it. Of course judging how stable it is is more an art than a science so they tend to err on the side of caution so many chips are stable at slightly higher speeds.

The reason that you don't see that many name brand computers with AMD chips in them is really pretty simple. 1) long term proprietary contracts between the companys and Intel. 2) Name recognition. (your mom basically knows what a pentium is...does she know what an Atlon is? thought not) But ask just about anyone who has built their own computer what type of CPU is in their setup. I'm guessing you'll find that at least 80% have an AMD chip of some sort. I do.

Actually last month AMD outsold Intel for desktop processors. And Dell is now the only one of the major suppliers that still don't use AMD.

Pentium-M was code-named "Banias", but is based off of the Pentium-III core which is based off the old Pentium Pro core.

Intel are working on a Pentium M based on the P4, or have already released them, I forget which.

If you're doing 32-bit calculations, they're just more expensive.

Not neccessarily true, the Athlon 64 also has some great 32bit processing that beat many of their standard 32bit chips, making the price worthwhile for just 32bit applications. Also they are future proof, the next couple of years will start seeing programs optimised for 64bit.

[klinky]

Chao intel has killed off NetBurst and will be using Pentium-M tech from here on out. This is the reason why they are changing their naming scheme because the Pentium-M has slower clock rates, but runs faster clock for clock than a Pentium4. Also uses quite a bit less power...


-Klinky

[LovEnPeaCE]

ok, back to the celeron vs p4 thing.......the celeron and p4 can both fit on the same motherboards because they are the same socket type(have the same number of pins in the same arrangement), skt.478. If you can fit a p4 on it, you can fit a celeron on it and vice versa, but this all depends on the motherboard. The motherboard might not be able to function with all of the different types of the p4 and celeron processor.

[ZeroSSJ999]

celerons are actually offsprings of p4, pretty a celeron is what you get when you mass produce proccessors, celerons infact are usualy some part of a defective p4, so i hear, and they work just fine, but just arent quiet as fast, not fast enough to make the cut, so they slap celeron on it..

[dwchang]

Where's DW when you need him?

I'm right here...lurking all along. I've kind of purposely not replied to things in Video hardware to see where things go and well...I've been lazy and not writing as much lately

Anyway, I guess I'll go with this topic-by-topic. First off the original question:

Pentium and Celeron: what's the difference?

Basically Celerons are shitty pentium IV's. There's no euphemism around it. They're just the crappy yielding PIV's and Intel needs to sell them. Think of it this way:

Say Intel wants to make Pentium IV's with 1 MB cache. Fabricating a 1 MB cache isn't 100% fullproof. You won't have a yield of 100%. You therefore will have units fall out that have one bit (unrepairable) failures. These are now 512 kb (or 256 kb) parts.

Intel will take this lost yield and then test them at those cache sizes and then sell them as Celerons. It basically makes up for those lost parts and they don't lose as much money. AMD did something similar with the (now dead) Duron brand.

Also as someone mentioned, Celeron's have a slower Front-side bus. This basically means these parts don't behave well at 400+ Mhz FSB and thus are downgraded in FSB accordingly.

Effectively if you have the money, don't go for the crappy Celeron or even *gasp* Durons. Just buy the namebrand version i.e. Pentium or Athlon. They're more stable and perform better. You get what you pay for.

Pentium-M

This one's easy. A Pentium-M is ~Pentium III. Sugarcoat it however you want, but that's what it is. Intel took the (much more stable and much better, both in power and performance) PIII core and made it mobile. As I said in parentheses, the PIII core is more stable and better at lower temperatures. Surprising I know since PIV is a bigger # than III, but the core of the III is FAR better (~13 pipeline stages vs. ~40 pipeline stages).

Anyway, to further illustrate this, ever wonder why Pentium-M's have frequencies below 2 Ghz while PIV's have 2.4+ Ghz parts...and yet the Pentium-M is more expensive? It's because the "slower" Pentium-M is the better performing part. As someone eluded to in this post:

Good news for those who are confused. Intel will be changing the names of the processors to better reflect actual performance rather than just the clock speed. Article

Intel has followed suit and now don't rely on "the Mhz myth." Kind of funny how they're FOLLOWING AMD after years of saying we were wrong and that Mhz = Performance. Any dimwit with any knowledge in Computer Architecture knows this isn't true and it's funny that Intel finally takes back their words and adopts the same performance modeling system we did...just took 'em 3 years.

I'm also glad to see someone else having a firm understanding of things:

All that said, all we have left (realistically) are the chips from the fine folks at AMD. From the evidence that I have, AMD manufactures their chips in such a way that the internal architecture of the chip is radically different from a standard Pentium equivalent, which allows it to operate MUCH more efficently then it's counter parts. There are benchmarks out the ass to prove that to you. Clock cycle per Clock cycle, AMD chips do more work, and cost LESS then Pentiums.

I couldn't have explained it better. For those of you "equation nuts," the basic computer architecture formula for performance is as follows:

Performance = speed (mhz) * efficiency (instructions per clock)

As Joykiller noted, Athlon chips do more work per clock and that's why a 2.0 Ghz Athlon is modeled as a "XP 2800" or something. It means it performs as well as a PIV 2.8 Ghz.

As I said earlier, A Pentium IV has 40 pipeline stages. This means an instruction must go through 40 stages prior to being "retired." Athlons have ~12 stages. If a pipeline stage is clocked at 2.8 Ghz it means it will run faster, however it has to go through 28 more stages compared to that which goes through 12 and runs at 2.0 Ghz. With a little math, you can see why an Athlon performs similarly (and better in some cases) to that of the Intel family.

The reason that you don't see that many name brand computers with AMD chips in them is really pretty simple. 1) long term proprietary contracts between the companys and Intel. 2) Name recognition. (your mom basically knows what a pentium is...does she know what an Atlon is? thought not) But ask just about anyone who has built their own computer what type of CPU is in their setup. I'm guessing you'll find that at least 80% have an AMD chip of some sort. I do.

Sadly he's right. Ask your grandma about computer or mention "intel" and you'll probably see them respond positively and with recognition. Ask them about "AMD" and you get ?_?. I should know considering my grandmother asks me where I work and I have to always say "Intel's competition."

Actually last month AMD outsold Intel for desktop processors. And Dell is now the only one of the major suppliers that still don't use AMD.

Well sorta. Now although I like seeing wins for my company, this is one that has been misquoted and misrepresented.

First off, I believe it was AMD outsold Intel for ONE WEEK, not month. Secondly, it was one really specific product line/business sector and not overall. Lastly...it's one week :-/.

Yeah you're right on Dell, but hopefully they'll crack. I mean from what I hear, IBM, HP, Sun and so on are really stickin' it to them and consumers are asking why they can't buy 64-bit processors now. I could go on and on about Dell, but I imagine that's part of my NDA.

While we're on the topic. How do the 64bit CPUs differ?

If you're doing 32-bit calculations, they're just more expensive.

Not exactly.

If you're talking about an Athlon64 then they cost exactly the same. The Athlon64 operates 32-bit mode just as well as a pentium IV or even the Athlon XP's. The benchmarks show this.

The only major difference is the registers are larger (i.e. 32 more bits). This means you can have bigger and larger calculations. Given I'm really simplifying things, but that's effectively it.

At the same time, as someone eluded, 32-bit performance is comprable if not better than current processors. You also get 64-bit processing (the future). I did some searching last month and I think you can get a 2.2 Ghz 64-bit Athlon for like 250 - 300 bucks. That's pretty cheap considering the performance.

In fact, I saw some benchmarks after the 939 package came out (two weeks ago?) and we now dominate almost every benchmark and Intel still only wins a handful (and by a small margin). Tom's Hardware also eluded that Intel doesn't have anything in its pocket till like Q4'04. I somewhat doubt that, but hopefully it's true and AMD will maintain it's lead .

Man and I remember when were all scared of the Power behemoth Prescott .

Speaking of copying (like I said earlier), you guys HAVE TO know that Intel is copying our architecture for 64-bit x86 too right? They were so firm on the Itanium, but finally folded and are designing their own based on our ISA. Too bad consumers won't realize this and they copied us...again :-/.

Anyway, I think that covers things. Now I realize (again) why I don't write here often

[Kalium]

Speaking of copying (like I said earlier), you guys HAVE TO know that Intel is copying our architecture for 64-bit x86 too right? They were so firm on the Itanium, but finally folded and are designing their own based on our ISA. Too bad consumers won't realize this and they copied us...again :-/.

I remember hearing about that. I also remember mention being made that AMD has used RE in the past to get ahead.

If you're doing 32-bit calculations, they're just more expensive.

I was actually referring to the price of the chip, meaning that for the price of a 64-bit chip you can get a 32-bit one that will offer better 32-bit performance.

Anyway, I think that covers things. Now I realize (again) why I don't write here often.

Yes it does, and quite nicely. Do you not post here because you write too much and it gets annoying? Is it that much of a pain to share some of your highly concentrated and valuable clues with us *sniff*?

[mckeed]

Yes, Intel is copying the 64 bit architecture, but that should be no surprise to AMD. AMD itself started in the first place by reverse engineering the 286 and 386 processors as AMD was just the 2nd source of Intel chips back in the day when Intel had to outsource production as companies didn't like the idea of only one company making the chips and not in sufficient quantities.

[paizuri]

Yes, Intel is copying the 64 bit architecture, but that should be no surprise to AMD. AMD itself started in the first place by reverse engineering the 286 and 386 processors as AMD was just the 2nd source of Intel chips back in the day when Intel had to outsource production as companies didn't like the idea of only one company making the chips and not in sufficient quantities.

Yeah, not only can Intel make AMD compatible chips, but AMD most likely wouldn't be able to sue them unlike when AMD did it to Intel years ago. I guess what goes around comes around.