Overclockers rejoice as Intel launches unlocked silicon

Intel has launched i5 and i7 processors without the speed limit. Photo / Supplied

In a move that looks set to delight PC gamers and hard core tinkerers, Intel has launched two new affordable unlocked processors that are built from the ground up to be very overclockable.

Prior to launching the new chips, Intel had only offered unlocked version of their high-end "Extreme Edition" CPUs. With the announcement of the Core i7-875K and Core i5-655K processors (which were both announced at Computex 2010), Intel is finally making over clocking available on its midrange CPUs.

Both of the new processors are veritable powerhouses and come with fully adjustable memory, core clock and power settings, meaning overclockers get more control over how much they can crank up the speed without sacrificing stability.

The Core i7-875K is a quad-core CPU with hyperthreading enabled, 8MB of cache, dual-channel DDR3-1333 memory controller and 16 lanes of integrated PCIe. Clocking in at a base frequency of 2.93 GHz, the Core i7-875K can run 3.6 GHz via its turbo mode.

The Core i5-655K also sports a built in Intel HD Graphics controller, but has only 4MB of cache. This said, the Core i5-655K has the same two channel memory controller and PCIe implementation as its bigger Core i7 counterpart. The Core i5-655K clocks in at 3.2 GHz and up to 3.46 GHz via its turbo mode.

The big news for overclockers, however, is that they will also now be able to adjust the Turbo Mode frequencies to increase speed when performance is needed.

The silicon tinkerers also gain the ability to push a lot more power through the CPU if necessary and the voltages will even scale dynamically depending on Turbo Mode settings.

In practice, clocking up the core i7-875K proved dead easy. With its unlocked multiplier I was able to increase its clock speed above the 3.5GHz mark whilst using a stock standard Intel cooler, just by changing the Host Clock Frequency setting, on my motherboard.

Compared to my previous overclocking attempts, this seemed a lot easier and most importantly, less likely to damage the CPU as I wasn't mucking about with core voltages and other settings.

Lacking a heavier duty cooler did mean that I was unable to push the Core i7-875K any harder, even though I suspect I'd barely begun to touch its untapped raw horsepower.

As with previous Core i7s, the Core i7-875K has four processor cores and supports Intel's Hyper-Threading (HT) technology, which allows it to tackle up to eight chores simultaneously (which equates to significantly smoother multi-tasking and zippier performance when using hyperthreading optimised applications such as Photoshop).

Manual overclocking aside, its base clock speed (2.93GHz) can be ratcheted up automatically using Intel's Turbo Boost feature, which automatically runs any of its four CPU cores at higher clock speeds when needed.

If you're looking for a snappy yet affordable CPU to pair with a decent graphics card for a gaming rig, or simply want CPU-intensive apps such as Photoshop to run smoother and faster, chances are that you'll be well pleased with either the Core i7-875K or if on a budget, the Core i5-655K.

What is overclocking?

Whilst most PC owners have probably never heard of overclocking, it has long been the stuff of geek one-upmanship. At its simplest, overclocking is essentially taking a computer component (such as a processor) and running it faster than what is recommended by the manufacturer.

Most computer components are typically tested and rated for a specific performance levels and as most hardcore PC users will tell you, most are also underrated for increased reliability.

Overclocking simply takes advantage of this remaining headroom to squeeze what are sometimes high-end performance gains out of PC mid-range PC hardware.

Performance gains aide, there are also potentially serious drawbacks to overclocking for the uninitiated. The biggest drawback to overclocking some computer components is that you can void its warranty.

Some over clocked component parts can also be pushed beyond their rated limits, shortening their lifespan.

Worse still, should the overclocked component be driven too hard or not cooled properly (good cooling equipment is a must when overclocking), they can burn out, taking out other PC components with them.