Introduction and Core processors
Not so long ago, processors were judged largely by raw clock speed alone, a measure of how many calculations the chip is capable of performing in the space of a second. As megahertz (MHz) speeds have given way to today's faster gigahertz (GHz) processors, however, there's more to consider than just how speedy a slab of silicon can be at doing math.
These days, it's all about cores, which have allowed chipmakers like Intel to boost speed by splitting tasks across a number of processors living on the same die. Coupled with software designed to take advantage of multiple cores, such processors can wind up tackling intensive work faster than ever before.
However, shopping for a new processor isn't quite as simple as picking the one with the fastest processor speed and the most cores, but we're here to help outline the subtle (and not-so subtle) differences before purchasing your next PC. Let's start with a bit of backstory on what Intel has to offer - but if you're just curious which processors are the fastest currently available, jump straight to the wrap-up to find out.
For the purposes of our discussion, we'll focus strictly on central processing units (CPUs) manufactured by Intel, who is considered the market leader powering the majority of Windows and Mac OS X-based systems available. (Competitor AMD typically costs less, and is therefore more commonly found on budget-priced Windows boxes.)
Intel also makes processors dedicated to servers and embedded devices, as well as an increasing number of mobile devices. While these chipsets are classified in many of the same product families - familiar names like Xeon, Atom and Core i3, i5 or i7 - our focus will mostly be on the traditional desktop and notebook CPUs the company is best known for.
Core i3, i5 and i7
The most popular Intel processors would be the Core "i" series, now in its fifth desktop generation with the current Broadwell code name. A successor to the Core 2 processor introduced in 2006, the "i" series is broken into three categories that could be generally classified as "good, better and best."
Despite their names, Core i3, Core i5 and Core i7 do not signify how many processing cores each has - rather, they are simply designations that classify how many stars Intel would assign to a given chip, based upon expected performance. (Intel abandoned the previous star rating system in favor of this numeric designation.)
One of the easiest ways to categorize Intel Core processors is to look at how Apple has implemented them into its line of popular notebooks. Core i7 processors are used to power the high-end 15-inch MacBook Pro with Retina Display, while Core i5 processors are used in a variety of speeds for the less expensive 13-inch MacBook Pro with Retina Display, as well as the 11-inch and 13-inch MacBook Air models.
Apple doesn't currently utilize the lower-end Core i3 processor in its notebook or desktop lineup, but plenty of Windows OEMs certainly do - if you happen to see an advertisement for a system with a price that appears too good to be true, there's a good chance it may powered by something from the Core i3 family.
What's in a core?
At the higher end, Core i7 was actually introduced first in 2008, with clock rates of 1.6GHz at the lower end of the spectrum, currently up to as fast as 4.4GHz. The i7 category actually breaks down into two camps: Processors that consume a more modest amount of power (45 to 130 watts) with quad cores, and those intended for desktop systems (with power consumption between 130 and 150 watts) that add hexa-core and octa-core options (more on that in a moment).
The next step down is Core i5, the popular midrange processor lineup Intel first introduced in 2009. With clock speeds ranging from 1.06GHz to 3.6GHz, Core i5 chips are available in dual-core and quad-core configurations with surprisingly efficient power consumption (17 to 95 watts).
Last but not least, Core i3 is somewhat of the new kid on the motherboard, introduced in 2010 as a cost-effective, dual-core option capable of between 2.4GHz and 3.7GHz. While the Core i3 may fall short in raw power, it more than makes up for that in low power consumption (between 35 and 73 watts), but generally speaking, this series will be found in budget-priced systems.
Pentium: gone but not forgotten
The Core lineup certainly wasn't Intel's first rodeo - far from it! The company introduced the Pentium line way back in 1993 with a meager clock rate starting at 60MHz (yes, megahertz!) and not a second core in sight until 2005, when the Pentium D/Extreme Edition (EE) served up a dual-core CPU capable of running multi-threaded applications.
A year later, the first-generation Intel Core processor would be introduced, and the writing was on the wall for the Pentium lineup, which was finally phased out in 2009. Intel Core and Core 2 CPUs became a big step toward the current Core i3/i5/i7 lineup.
Along the way, Intel introduced a dizzying variety of Pentium-class chips, including the MMX (1996-1999), Pentium Pro (1995-1998), Pentium II (1997-1999), Pentium III (1999-2003), Pentium 4 (2000-2008) and the Pentium M (2005-2008).
The rest of the family
Celeron, Atom and Xeon
With all this talk about Pentium and Core processors, it's almost easy to overlook three other members of the Intel processor family. Two of them are aimed at less-expensive devices, while the third can be found in some of the most powerful desktops and workstations around.
The elder member of the group is the relatively low-powered Intel Celeron, which first debuted in 1998 and eventually wound up getting a fairly bad reputation during the ill-fated "netbook" era. With clock speeds ranging from 266MHz all the way up to 3.6GHz, this single- and dual-core performer is amazingly still a member of the Intel production line, although it has largely been supplanted by the Core i3 series.
More focused on energy savings than raw power, the Intel Atom line has found a home in recent years within network-attached storage (NAS) boxes as well as mobile devices, robotics and health care equipment. First introduced in 2008, the Atom line has covered the gamut of clock speeds, from 800MHz up to 2.13GHz.
That leaves only the "big daddy" of Intel's processor lineup, the Xeon. Since 1998, the Xeon has been at the core of top-of-the-line PCs such as the Mac Pro, starting out with clock speeds in the 400MHz range and most recently maxing out at 4.4GHz, available in single, dual, quad, hexa and octa-core configurations.
Cores to the max
By now you might be wondering what all the fuss is over multiple cores. As their names might indicate, dual-core means two cores, quad-core means four, hexa-core means six and octa-core delivers a whopping eight cores for the maximum processing power around.
Quad-core is increasingly becoming the norm across the board, while hexa-core and octa-core processors are reserved for the most expensive desktop systems. Generally speaking, the more cores your CPU has, the better the performance it will be capable of - although software and even the type of internal storage can have a big impact as well. (After all, solid-state flash storage is faster than traditional hard drives.)
Ultimately, the number of cores will depend upon what you need to do with the system in question. Casual web browsing, email and basic productivity tasks will all perform respectably on Core i3 or even older Core 2 Duo processors, while Core i5 should be considered the absolute minimum for more artistic endeavors such as Adobe Photoshop or 3D modeling software.
Hardcore gamers probably have the most to gain from Core i7 processors, although computing tasks like video encoding or editing and music creation will certainly benefit as well.
More than just cores
There are also other considerations when comparing processors. For many chips, Intel uses hyper threading (HT) technology that allows the processor to perform two instructions (or threads) at the same time. The result is performance that approaches that of two separate processor working in tandem.
Core i7 processors all support hyper threading with a minimum of four cores, for a combined total of eight possible threads running at the same time. Coupled with a larger cache size and typically more system RAM, and it's not hard to see why Core i7 is quite popular with power users.
Other technology like Intel's Turbo Boost allows the processor to dynamically ramp the clock speed up or down when needed. Turbo Boost offers a significant advantage for Core i5 chips - which all include such technology - over Core i3 processors, which do not.
The fastest processors available
What's in a number?
It's also worth noting that not all Intel Core processor brands are the same, even if they carry the i3, i5 or i7 modifier. There's also an alphanumeric code used to describe the processor model, and each one can tell prospective buyers something about what they can expect from it.
For example, an Intel Core i7-4770K model number breaks down as such: The first number after the brand modifier indicates the generation (in this case, the number four equals fourth-generation), followed by a three-digit numeric stock keeping unit (SKU) that helps differentiate each for the retailer.
The processor may include one or more product line suffixes. In the above example, the trailing "K" signifies an unlocked desktop model with a CPU capable of performing to peak potential, versus other letters like S or T, which are optimized for "lifestyle" performance or power, respectively.
You may have heard Intel processors also referred to by their internal code names. Although you'll rarely see them marketed that way, code names like Sandy Bridge, Ivy Bridge and Haswell have become part of the tech media lexicon in recent years. The code names simply refer to a newer, higher performance version of the same processor type, rather than an entirely new CPU.
See you next year
Much like the notebooks, desktops and mobile devices they power, Intel releases new processors on a near-annual basis, so whatever you purchase today will no longer be cutting edge a year from now.
With that wisdom in mind, a notebook or desktop powered by an Intel Core i5 or Core i7 is likely to be the best investment, unless the buyer is capable of shelling out thousands of dollars for something with Xeon inside and plans to use it for several years.
Rumors have been spreading that Intel plans to expand the popular Core series with something called i9, but to date the chipmaker seems content squeezing every bit of potential out of the Core i7 series, which offers the closest thing to future-proofing we're likely to get from a CPU.
One last piece of advice: No matter which computer you decide on, go with the fastest processor you can afford. After all, adding more memory or swapping in a larger SSD or hard drive is relatively easy compared to replacing the CPU, an option that really only exists for those building a system from scratch anyway.
Speed curious? Here's a look at the top three fastest Intel processors powering desktop and notebook computers, ranked according to 3DMark benchmark scores.
1. Intel Core i7-5960X (12540)
2. Intel Core i7-4960X (12480)
3. Intel Core i7-5930K (12440)
1. Intel Core i7-4870HQ or Intel Core i7-4860HQ (8430)
2. Intel Core i7-4940MX (7170)
3. Intel Core i7-4930MX (7070)