Whether you're constructing a budget workhorse or a high-performance rig, your search for the best hardware for your dream PC should start with the processor, or CPU. Your choice of CPU will influence a lot of the other decisions you make, since your ability to find a compatible motherboard, CPU cooler, and (to some extent) power supply will be affected by the processor’s specifications.
Intel Core i5-2500K ($240)
Though the 3.3GHz Core i5-2500K is a quad-core processor, it lacks Intel’s hyperthreading technology, so you won’t see the eight virtual cores that you can otherwise expect from Intel’s quad-core wares. It does offer Intel’s Turbo Boost, which automatically overclocks the processor to 3.7GHz when applications demand it, provided that the CPU hasn’t hit its maximum heat and power thresholds. You also get Intel’s integrated graphics, which have greatly improved in the Sandy Bridge era.
You could spend less on another Intel CPU, such as the $115 3.1GHz Intel Core i3-2100. But ultimately the Core i5-2500K will net you superior performance and improve the longevity of your PC. The K on the model number means it’s unlocked and ready to be overclocked, if you’re feeling adventurous. (You want to build a PC that will last a long time, and overclocking is a nice way to eke out a bit more power a few years from now, if you’re careful.) The 2500K costs about $25 more than the standard locked CPU, however; if you have no intention of ever dabbling with your processor’s frequencies, that’s money you can save.
AMD FX-4100 ($110)
To save even more cash, you could choose the new 3.6GHz FX-4100. This quad-core CPU sits at the bottom of AMD’s recently launched Bulldozer line. It offers AMD’s Turbo Core technology, which follows the same principles as Intel’s Turbo Boost: When your CPU has a bit of thermal headroom, it will automatically overclock up to 3.8GHz, to give applications a bit more oomph.
The FX-4100 is unlocked. The Bulldozer line is generous with overclocking too; you can expect substantial CPU frequency gains with minimal effort. In real-world usage, this CPU isn’t nearly as fast as Intel’s Core i5-2500K, but given that it’s half the price, you probably expected that.
Intel Core i7-2600K ($320)
If you’re building a PC for gaming, video editing, or other CPU-intensive tasks, I recommend going with the highest (reasonable) entry in Intel’s Sandy Bridge line, the 3.4GHz Core i7-2600K. This quad-core processor is equipped with Intel’s hyperthreading technology, which provides eight virtual threads for your applications to play with. The CPU includes Intel’s Turbo Boost and integrated graphics technologies, as well. If your work (or play) is graphically intensive, however, it remains in your best interest to buy and install a proper discrete graphics card, even with a CPU this formidable.
Have plenty of room in your performance-PC budget? Take a look at the Core i7-3930K, Intel’s new Sandy Bridge Extreme Edition six-core processor. With hyperthreading, this CPU offers 12 virtual cores, and it delivers incomparable levels of performance. Note, though, that it’s priced at $1000--which puts it out of the reach of most mortals--and that it requires a motherboard supporting the X79 chipset.
AMD FX-8150 ($240, pictured)
If you prefer to stay on AMD’s side, check out the FX-8150. Although this processor currently resides at the top of the company’s much anticipated Bulldozer line, in most situations it barely outperforms the Intel Core i5-2500K. It’s very friendly to overclockers, however, allowing you to make substantial CPU frequency gains without stressing your machine’s CPU cooler extensively.
Why choose an AMD processor if you’re not planning to overclock? The FX-8150‘s price has fallen considerably since it launched, so buying this CPU would leave you with extra funds to save, or to splurge on pricier components elsewhere. And if you shop judiciously, AMD-ready motherboards tend to be a bit less expensive than their Intel counterparts.
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