Tuesday, May 8, 2007

Dual Core, Core Duo, oh my!

Summary: A lame attempt to explain the major differences between various Intel processors.

Because I work at Intel, my friends believe that I know everything about computers. Which laptop is the best? Which processor is the fastest? These are the types of questions I hear repeated over and over.

I must confess that I do not really know much about computer hardware. For several years my expertise in processor architecture could be summarized in two statements: (1) Pentium is better than Celeron, and (2) AMD can beat Intel in processor performance (well... it did until recently). Surprisingly, these insights were enough to let me hold the status of a tribal computer expert for several years, but I started to feel like I was falling behind the latest advances in processor technology. Dual Core, Core Duo, Core 2 Duo, Centrino Duo... Which one is better? How is Dual Core different from Core Duo? What about Core 2 Duo? If "Duo" means "Two", what does "2 Duo" mean? How is Core Duo related to Centrino Duo? Since there is Core 2 Duo, shouldn't there be Centrino 2 Duo? And what is Centrino anyway?

[The question why Intel abandoned a simple and logical naming convention in favor of something destined to confuse keeps bugging me. Isn't the sequence 80286, 80386, 80486, Pentium II, Pentium III, Pentium IV (and so on) easier to follow? Sure, most people can probably guess that Core 2 Duo is better than Core Duo (which is correct), but for less savvy users, the difference between Dual Core and Core Duo is murky because the names sound so similar. I suspect that Intel chose to sow confusion intentionally. The bright minds in Sales and Marketing must have followed the path of the auto makers, who -- according to some theories -- use different trim line naming conventions (DX, LX, LS, ES, EX, Si, CE, LE, and so on) to protect self-esteem of customers buying cheaper models. Unless you are a car enthusiast, without a research you will not know which trim is more expensive and which one is the cheapest. For example, I know that Honda Accord EX is more advanced than DX, but I cannot remember which one is more basic: Toyota Corolla DX, LE, or CE. If I drive a cheaper trim line model -- so the theory claims -- my self-esteem does not get hurt, as long as I believe that the trim classification is not obvious to others.]

So, which processor is best? Which one is good enough? Which one would I recommend to buy? I did some research and want to share what I found out. I will try to keep it short and simple to make the information understandable for non-technical readers. If you need to know more in-depth details, read the referenced articles. [I'm covering only Intel processors because I'm more familiar with the Intel product line. If someone points me to similar information for AMD, I'll gladly add a reference.]

If getting the best processor is a top priority in your computer buying decision, look for a system which bears the Intel Core 2 Duo logo.


According to industry-wide consensus (see reports from C|NET, ExtremeTech, Hexus, Linuxhardware.org, PCSTATS, PC World, Reg Hardware, Techreport, Tom's Hardware Guide, and others), Intel Core 2 Duo is the current leader in the processor race (at the time of writing).

Buyers seeking the ultimate computing expirience (such as gamers) should benefit from Core 2 Extereme or Core 2 Quad.


If the names of these processor lines do not ring any bells, it's unlikely that you will appreciate their performance, so if you want to avoid paying premiums, just stick with Core 2 Duo; it will serve you just fine. You should be able to find a decent Core 2 Duo-based laptop (15"+ screen, decent graphics card, 256MB video memory, 1GB+ RAM) for around $800-$1,000* (on sale, after discounts and rebates), but you may need to do some research.

Sometimes, systems powered by the Intel Core 2 Duo (and Intel Core Duo) processors, bear the Intel Centrino Duo (or a newer Intel Centrino Pro) logo.


The Intel Centrino technology provides a more efficient combination of a processor and other hardware components (wireless card, motherboard). Centrino aims primarily at improving power efficiency, so you will find it mostly (if not only) in laptops and other mobile devices. All Centrino Duo or Centrino Pro-powered models run on Intel Core 2 Duo (or Intel Core Duo) processors. If you do not see the word Duo (or Pro) on the Centrino label, be aware that this system is not based on Core 2 Duo (or Core Duo). [I wish Centrino based on the Core 2 Duo processor line were named Centrino 2 Duo to make the relationship to Core 2 Duo more obvious.]

As the name implies, Intel Core 2 Duo processors include two processors on a single chip (Duo means two processors, number 2 means second generation), but so do other processors, such as Intel Core Duo, Pentium Dual Core, and even Pentium D.

Intel Core Duo (notice that there is no number two in the middle) is a cheaper sibling of Core 2 Duo.


The main difference between Core Duo and Core 2 Duo is that Core Duo does not support the 64-bit (x86-64) architecture, so you will not be able to run 64-bit Windows Vista on it. When given a choice between the two, for the price difference around $50, I would pick a Core 2 Duo-based system. If the price difference is over $75, unless running 64-bit Windows Vista is a requirement, I would consider Core Duo. [Because of limited software and hardware support, as well as unproven performance benefits, I would not recommend 64-bit Windows to most users at this time. Until the 64-bit platform gains wider acceptance and more 64-bit applications (in particular, device drivers) are available, you can save money and opt for a Core Duo processor.]

Intel Pentium Dual Core is another attractive option for bargain hunters. It is similar to Core Duo, but comes with a smaller cache memory (larger cache is always better).

Dual Core and Core Solo-based laptops can sometimes be found on sale for around $600-$700*.

Intel Core Solo should be even cheaper than Intel Core Duo, but because it runs only one core, I would not recommend this processor to an average buyer, unless it is offered at a budget price (for basic computing needs).


Intel Pentium D is the first multi-core (i.e. dual-core) processor from Intel. Although, it has been discontinued, you can still find it in budget systems.

Intel Pentium M belongs to the older architecture released before Intel Core (Intel Core Solo and Intel Core Duo). It was designed for mobile computers and can be paired with the original Intel Centrino technology.


Even though they do not support multi-core architecture, newer models of Pentium M are still offered for budget-minded users.

Intel Celeron is currently offered in two versions: Celeron D and Celeron M.


While Celeron M follows the Pentium naming convention (M means mobile, similar to Pentium M), Celeron D has nothing in common with Pentium D. Because of the smaller cache size, I would not recommend any system that uses Celeron D, unless it is intended to replace a broken typewriter and offered at a really cheap price (around $200 for a desktop without a monitor/keyboard/mouse). Celeron M can be considered for sub-$400 laptops, but it may worth spending extra $100-$200 on a Pentium or Core-based system.

On a final note, I need to mention that everything I said above is no more than a rough guideline; it may not always be accurate. For example, a well-designed newer Celeron-based system can be better than an older and not-as-well-designed Pentium-based system. Or a certain system running on a Core Solo processor can give you a better bang for the buck than a different system running on a Core Duo processor. Other components, such as size of memory, type of motherboard, graphics card, and hard drive speed, can affect the system performance more than minor processor differences. If you really want to know pluses and minuses of the system you're considering to buy and compare it with the competition, I would recommend checking reviews of the exact processor model (use your favorite search engine to find model reviews). Pay special attention to problem areas (like Pentium 4 heat problem). Also, check the overall system configuration and critical components (at least, memory and graphics card).

Additional references:
A tale of two laptops, or can I run Vista on a Celeron
What is dual core?
Desktop Processors
Laptop Processors
Processor roadmap (desktops)
Processor roadmap (laptops)
Intel Core (CPU)
Intel Core 2
Intel Loses its Will to Viiv
Intel announces simplified product-naming scheme

For some fun, watch these cool short Intel video ads directed by Christopher Guest:

Video Ad #1 (2:59)
Video Ad #2 (2:33)


*Since the time of publishing, laptop prices have dropped, so at the time of this comment (Jan 1, 2008), you may be able to find a nice Core 2 Duo-based laptop for around $600-$700 or even less (on sale, after rebates).

9 comments:

Ankit said...

Thanks for sharing this wonderful information Alek.
I didn't even knew about so many processor types earlier.

I have a HP laptop which runs Intel(R) Core(TM) 2 Duo processor T7250 (2.00 GHz, 2 MB L2 Cache, 800MHz FSB)

Can you please let me know your views on its performance?

Thanks in advance.
Ankit.

Alek Davis said...

Thank you, Ankit. From what I can see, T7250 is a pretty decent processor, although not top of the line among the Core 2 Duo family, but still not bad. One thing that I do not quite understand is why it has 2 MB of cache while its predecessor (T7200) and successor (T7300) both have 4 MB (more cache is always better). Otherwise, it's a fine CPU.

Ankit said...

Thanks Alex. I need to clarify this from Intel I guess.. :)

Ankit said...

Alek, please tell me one more thing.
My laptop logo says "Intel Centrino Duo" and its configuration says its an Intel Centrino Core 2 Duo....Does that mean the same?
Does it run Core 2 Duo only?

Alek Davis said...

Yes, it's pretty much the same. It's a bit confusing, but in most (if not all) cases, "Intel Centrino Duo" (Intel term) indicates that the laptop runs on a Core 2 Duo-based processor. "Centrino Core 2 Duo" (I guess, it's the manufacturer's term) is less ambiguous; it more accurately indicates that the laptop uses the Centrino technology and is based on a Core 2 Duo processor. I like "Centrino Core 2 Duo", but it's not an official Intel trademark (or at least, it wasn't when the sticker with the logo was printed.

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smamishinternut said...

In your opening, you wondered why Intel moved from simply numbers to denote speeds to marketing buzzwords like Pentium. I remember this back in '97 in highschool and the reasoning was that you can't patent numbers like you can names.

I found some supporting text on wikipedia: Pentium is a registered trademark that is included in the brand names of many of Intel's x86-compatible microprocessors, both single- and multi-core.[1] The name Pentium was derived from the Greek pente (πέντε), meaning 'five', and the Latin ending -ium, a name selected after courts had disallowed trademarking of number-based names like "i586" or "80586" (model numbers cannot always be trademarked[2])
http://en.wikipedia.org/wiki/Pentium

buildmaestro said...

In your opening, you wondered why Intel moved from simply numbers to denote speeds to marketing buzzwords like Pentium. I remember this back in '97 in highschool and the reasoning was that you can't patent numbers like you can names.

I found some supporting text on wikipedia: Pentium is a registered trademark that is included in the brand names of many of Intel's x86-compatible microprocessors, both single- and multi-core.[1] The name Pentium was derived from the Greek pente (πέντε), meaning 'five', and the Latin ending -ium, a name selected after courts had disallowed trademarking of number-based names like "i586" or "80586" (model numbers cannot always be trademarked[2])
http://en.wikipedia.org/wiki/Pentium

Alek Davis said...

Thanks for the info. Kinda makes sense. If only they used something less similar (like "dual core" vs. "core duo").