Recently, a client of mine mentioned that he was planning on equipping his outside sales team with new laptop computers and asked me to look into mobile CPUs and let him know which one I would recommend. When I asked him for more details on what features he was looking for or if there was a particular brand he was interested in, he told me that before he made any further decisions, he really wanted to get a handle what was what in the mobile CPU arena.

He then confessed that he had begun to explore laptops and instead of learning more had become more confused than when he started. He said that his initial investigations turned up over 30 different CPU variations carrying such names as Centrino Mobile Technology, Mobile Intel Pentium, Pentium M, Celeron M, Mobile AMD Athlon, and Mobile AMD Sempron. Further complicating the picture was a large number of model numbers associated with each one of these brand names.

Once I began my own exploration, I too discovered that when you take a look at laptops from more than one vender, there really are bewildering number of brand names and model numbers attached to the mobile CPUs on laptop computers. However, as I began compiling a list and sorting through it, the first thing that I discovered was that a lot of the confusion can be attributed to marketing techniques used to describe mobile CPUs in the various laptop brands.

Even after separating the wheat from the chaff I discovered that there was still a lot to sort through when looking at mobile CPUs. As such, in this article, I'll provide you with some basic information that will help you to begin to recognize the differences and get you off on the right foot when analyzing the current crop of mobile CPUs. I'll then point you to an assortment of links on both the Intel and AMD sites where you can dig deeper into the details on the various mobile CPUs.

Intel Pentium M

The Intel Pentium M processor family was specifically designed for laptop computers. This processor, which comes in a number of variations, is smaller in size and runs cooler than its desktop counterparts thus allowing for thinner and lighter laptops.

In addition, it has enhanced power management features, known collectively as SpeedStep technology, that are designed to provide laptop computers with longer battery life. SpeedStep works by dynamically throttling back system bus ratios, core operating voltage, and core processor speeds when the demand for CPU usage drops below a certain level.

In addition to the SpeedStep technology as a means of lengthening battery life, Intel also has several Pentium M processors that run at lower voltages. These processors come in two classes--Low Voltage and Ultra Low Voltage--and are specifically designed for laptops that will run on battery power the majority of the time that they are in use.

In order to differentiate between all of the members of the Pentium M processor family, Intel uses processor numbers with each number representing a set of features that include clock speed, architecture, Front Side Bus speed, and the amount of L2 cache.

As you can imagine, when looking at various advertisements for laptops this numbering scheme can be very confusing--especially when you consider the fact that not all the numbers are represented in any one particular advertisement. However, when the processor numbers are presented together as in tables A, B and C, it's a lot easier to make sense of the various processors.

Table A

Processor Number Clock Speed Front Side Bus Speed L2 Cache
705 1.50 GHz 400 MHz 1 MB
715 1.50 GHz 400 MHz 2 MB
725 1.60 GHz 400 MHz 2 MB
730 1.60 GHz 533 MHz 2 MB
735 1.70 GHz 400 MHz 2 MB
740 1.73 GHz 533 MHz 2 MB
745 1.80 GHz 400 MHz 2 MB
750 1.86 GHz 533 MHz 2 MB
755 2.00 GHz 400 MHz 2 MB
760 2.00 GHz 533 MHz 2 MB
765 2.10 GHz 400 MHz 2 MB
770 2.13 GHz 533 MHz 2 MB
Intel Pentium M Processor family

Table B

Processor Number Clock Speed Front Side Bus Speed L2 Cache
718 1.30 GHz 400 MHz 1 MB
738 1.40 GHz 400 MHz 2 MB
758 1.50 GHz 400 MHz 2 MB
Intel Pentium M Processor Low Voltage family

Table C

Processor Number Clock Speed Front Side Bus Speed L2 Cache
713 1.10 GHz 400 MHz 1 MB
723 1.00 GHz 400 MHz 2 MB
733 1.10 GHz 400 MHz 2MB
753 1.20 GHz 400 MHz 2 MB
Intel Pentium M Processor Ultra Low Voltage family

Desktop processors in laptops

While the focus of this article is on Mobile CPUs, keep in mind that you can find the standard Intel Pentium 4 processors in laptop computers. Laptops that use the Pentium 4 processors are ideal for situations when you're looking for a performance-based portable desktop environment that primarily runs from an AC connection power rather than a real mobile computer that runs primarily from battery. Of course, these laptops will be heavier and not as efficient on battery consumption as the Pentium M processors.

Intel Centrino Mobile Technology

The name Centrino is often confused as the name of yet another processor, when in fact that's not the case. On the contrary, the Intel Centrino mobile technology is a actually a brand name for a set of Intel technologies that combines the Pentium M processor, the Intel 855/915 chipset, and Intel PRO Wireless Mini-PCI card to provide a mobile computer solution.

Of course, the Pentium M processor allows smaller, lighter systems with long battery life and the Intel PRO Wireless mini-PCI card provides built in connectivity to 802.11 wireless networks. As such, you can find Centrino-branded systems that use any of the Pentium M processors listed above in tables A, B, and C.

Intel Celeron M

You're probably already familiar with the Celeron processor, which as you know is essentially a scaled down Pentium processor which lacks some of the high performance features and designed for low cost computers. These scaled down performance features are reflected in lower clock speeds and a smaller L2 cache.

Therefore, it's easy to see that the Celeron M processor is simply a version of the standard Celeron chip that includes that same type of power conservation and size features as the Pentium M processors.

Just like the Pentium M processors, the Celeron M processors come in a variety of processor numbers including Ultra Low Voltage versions. You can see all the current Celeron M chips in Table D and E. Again, it's a lot easier to make sense of the various Celeron processor numbers when they are presented together in tables.

Table D

Processor Number Clock Speed Front Side Bus Speed L2 Cache
310 1.20 GHz 400 MHz 512 KB
320 1.30 GHz 400 MHz 512 KB
330 1.40 GHz 400 MHz 512 KB
340 1.50 GHz 400 MHz 512 KB
350 1.30 GHz 400 MHz 1 MB
360 1.40 GHz 400 MHz 1 MB
370 1.50 GHz 400 MHz 1 MB
Intel Celeron M Processor family

Table E

Processor Number Clock Speed Front Side Bus Speed L2 Cache
333 900 GHz 400 MHz 512 KB
353 900 GHz 400 MHz 512 KB
372 1 GHz 400 MHz 512 KB
Intel Celeron M Processor Ultra Low Voltage family

Mobile AMD Athlon 64

The Mobile AMD Athlon 64 processor is a part of AMD's new family of 64-bit architecture chips that are designed to be compatible with today's hardware and software yet provide smooth transition to the world of 64-bit computing. However the Mobile version of the processor is smaller thus allowing for the design of thinner and lighter laptops. Furthermore, the Mobile AMD processors consume less power via the AMD PowerNow! Technology, which shifts processor between varying levels of performance based on application demand. This technology also allows the processor to dissipate less heat thus it runs cooler and makes for a quieter laptop.

The line of Mobile AMD Athlon 64 processors are differentiated by using model numbers, as shown in Table F, where each number represents a set of features that include clock speed, architecture, HyperTransport Technology speed, and the amount of L2 cache.

Table F

Model Number Clock Speed HyperTransport Technology Speed L2 Cache
2800+ 1.6 GHz 1600 MHz 1 MB
3000+ 1.8 GHz 1600 MHz 1 MB
3200+ 2.0 GHz 1600 MHz 1 MB
3400+ 2.2 GHz 1600 MHz 1 MB
Mobile AMD Athlon 64 Processor family

Mobile AMD Sempron

The Mobile AMD Sempron processors are essentially a scaled down versions of the Athlon processors which cut back on some of the high performance features making them ideal for lower cost laptops. These scaled down performance features are reflected in lower clock speeds and smaller L2 caches.

The line of Mobile AMD Sempron processors are differentiated by using model numbers, as shown in Table G, where each number represents a set of features that include clock speed, architecture, HyperTransport Technology speed, and the amount of L2 cache.

Table G

Model Number Clock Speed HyperTransport Technology Speed L2 Cache
2600+ 1.6 GHz 1600 MHz 128 KB
2800+ 1.6 GHz 1600 MHz 256 KB
3000+ 1.8 GHz 1600 MHz 128 KB
Mobile AMD Athlon 64 Processor family

More information

If you want to learn more about the technologies used in the mobile Intel and AMD processors, check out these links: