Core Goes Mobile
While the new Core brand products in the i3, i5, and i7 brands came out for the desktop first, they are now also available in laptops. The parts which are placed into laptops are often different from the desktop parts, however.
This guide to the mobile versions of the Core i3, i5, and i7 processors breaks down the CPU lines so that you know which features each processor offers and decide on the best laptop processor for your needs.
This article has been updated to include the new second-generation "Sandy Bridge" Core i3/i5/i7 processors. That information is on the second page. Those are the latest processors available from Intel and quicker than the originals listed below, but you can still find the originals as manufacturers/retailers get through stock.
Mobile Core i3 500 Series
Based on the Arrandale design, which is a mobile version of the desktop Westmere products, the Core i3 500 series processors are the entry level mobile processor. They are dual core processors clocked between 2.13 and 2.26 GHz.
These processors do have hyper-threading, but they do not have Intel's Turbo Boost. They include an integrated graphics processor and 3 megabytes of L3 cache. While the Core i3 processors are entry level, they still have respectable performance.
Mobile Core i5 500 Series Ultra-Low Voltage
A special processor sub-set of the Core i5, this processor has a U added to its name to indicate it is ultra-low voltage. Currently there is only one processor of this type. It is a dual core processor with a clock speed of 1.06 Ghz. It includes hyperthreading and a very aggressive variant of Turbo Boost, although OEMs using the Core i5 ultra-low voltage processors will probably put caps on how aggressive Turbo Boost can be when the laptop is on battery power.
Mobile Core i5 400 and 500 Series
Despite the different numbers attached to the 400 and 500 series processors these processors are basically the same. These are Arrandale based processors with clock speeds which range from between 2.26 to 2.53 Ghz.
These processors are dual core processors with hyper-threading and Turbo Boost. The Turbo Boost feature is less aggressive on the 400 series processors. All of these processors include an integrated graphics processor and 3 megabytes of L3 cache. Performance is very good, and the higher end Core i5 processors are probably the fastest processors you'll find in sub-$1000 dollar laptops.
Mobile Core i7 600 Series Ultra-Low Voltage
Like the i5 U series processor, the Core i7 600 ultra-low voltage processors fill are meant for products with long battery life. These are Arrandale processors with clock speeds from 1.06 to 1.2 Ghz.
These dual core processors include hyper-threading and Turbo Boost. Their Turbo Boost is the most aggressive of any Turbo Boost on any mobile Core processor except the Core i7 Extreme, but will probably be capped by OEMs when the laptop is on battery in order to maximize battery life. All of these processors include an integrated graphics processor.
Mobile Core i7 600 Series
The Core i7 600 series actually consists of two separate model types, those being low voltage and standard voltage. The low voltage products have a L attached to their model names.
Besides power draw, however, these models are basically the same. They have clock speeds ranging from 2 to 2.66 Ghz. They are dual core processors with Turbo Boost and hyper-threading. The Turbo Boost feature is just slightly more aggressive on the low voltage products than the standard voltage ones. These processors all have 4 megabytes of L3 cache. Also, all of these processors include an integrated graphics processor.
On the next page: Intel's new mobile quad-cores.
Mobile Core i7 700/800/900 Extreme Series
These are the top of the line mobile processors. While broken up into the 700, 800, and 900 series, these processors are all based off Clarksfield designs and share the same features.
Clocked between 1.6 Ghz and 2 Ghz, these processors are quad core processors with hyper-threading and Turbo Boost. The Turbo Boost feature is very aggressive on these processors when two or fewer cores are active. The Core i7 700 products have 6 megabytes of L3 cache while the 800 and 900 series processors have 8 megabytes. These processors DO NOT include the integrated graphics processor found with the Arrandale based mobile Core processors.
Second-Generation Core i3
Though selection is limited so far (as of March 21st, Intel only lists the Core i3-2310M on the company's website) the new second-generation Core i3 can be expected to replace the current Core i3 as the common processor in mainstream laptops between $600 and $1000 dollars.
The second-generation Core i3, like all second-generation Core processors, can be easily identified by the 4-digital product name. The first and only new Core i3 is called the 2310M, but we can expect a full line will eventually debut with similar names such as 2320M, 2340M, and etc.
All second-gen Core i3s have two cores and support hyper-theading. You'll also find Intel's HD Graphics, which is now part of the processor architecture. As was the case before, Core i3 laptop processors do NOT have Turbo Boost.
Second-Generation Core i5
The majority of the second-gen mobile Core processors being released by Intel are mid-level or more expensive models, such as the Core i5. Currently Intel has has five processors listed, and that is sure to increase over time.
All of the second-gen Core i5 processors have two cores and hyper-threading, with clock speeds ranging between 2.3 and 2.6 GHz. Turbo Boost is included, so the clock speeds will ramp up at times to provide better performance. All of the Core i5 processors have Intel HD Graphics.
Most of the second-gen Core i5 processors are just slight variations of each other, with names such as Core i5-2520M. Intel does offer a Core i5-2510E, which is targeted towards embedded systems (so you won't likely see this processor in laptops, but instead in high-end tablets or all-in-one desktop computers).
Intel also seems to be getting rid of the U suffix to designate low-power parts; the Intel Core i5-2537M, for example has a base clock speed of 1.6 GHz and a 17 Watt Max TDP, as opposed to the 35 Watt Max TDP shared by the other second-gen Core i5 mobile processors.
Second-Generation Core i7
As with the previous generation of Core i7 mobile processors, the new models come in both dual-core and quad-core variants. But unlike before, the pleasant break-up between the dual-core and quad-core models is a bit murkier. Now, both dual-core and quad-core models exist in the same numerical series; Intel offers a Core i7-2620M and Core i7-2630QM. The only difference is the suffix. If the laptop you're looking at doesn't have the QM suffix in the processor name, it's not a quad-core processor!
The other naming convention to keep in mind is the last digit of the model name. If the last digit is an odd number (except for a 5) the processor is a low-power model with a lower clock speed and lower TDP. So the Intel Core i7-2635QM is a normal part; the Intel Core i7-2657M is built for ultraportables.
Confused? That's because the naming scheme is confusing. Just remember; if it ain't got a Q, it ain't a quad! And if the last digit is odd and not a five, the performance takes a dive while the battery thrives!
Note: The Intel Core i7 Extreme Edition is an exception. It is a quad, but it uses the XM suffix. You're not going to find that processor outside of high-end gaming laptops, however.
Otherwise, these processors all have similar features. They include hyper-threading, Turbo Boost, and Intel HD Graphics.
Now that the second-generation Core processors are out, they're the obvious choice. The new generation is up to 30% quicker than the first, depending on the task you're performing.
However, it may be awhile before these new second-generation processors saturate the laptop market. Laptop designs are a bit less flexible than design, so manufacturers sometimes must wait until a chassis update in order to release laptops with the new, quicker processor.
The Core i3 line remains the one your average user will be happiest with. It is quick and offers Intel's latest HD Graphics, but it is also relatively inexpensive. Users who want just a bit more power can spring for the Core i5, which adds quicker clock speeds and Turbo boost. The price of that upgrade may not be worth the money, however, unless you can think of a specific processor-hungry application that you frequently use.
The Core i7 remains the best choice for power users, but the second generation Core i7 quad-cores are more easily tamed for mobile use than their earlier cousins. Although clock speeds are lower on the base models, changes to Turbo Boost and an improved architecture make these processors much quicker than the first-generation model.
If you're interested in laptops based off the Core i7 products please see our guide to the best Core i7 laptops.