Intel overclock-
friendly Core i5-655K & i7-875K CPUs tipped
Wednesday, March 24, 2010
We’d already heard rumors from Intel themselves that they were considering some cheaper, overclock-friendly processors for release in the not too distant future, and now those leaky Taiwanese motherboard manufacturers have spilt a few more beans. They reckon two such CPUs are in the works, a 32nm dual-core Core i5-655K which should arrive in early June, and a 45nm quad-core Core i7-875K which will follow on in late July.
The tinkertastic chips would line up against AMD’s dual- and quad-core Black Label processors, which are known for being particularly amenable to overclocking. So far only Intel’s “Extreme” chips have made the process anything less than difficult, and they tend to command top-end prices. Incidentally, the Core i7-980X Extreme – which we benchmarked with impressive results in the iBuyPower Paladin S earlier in the week – is apparently in short supply, with Intel increasing channel pricing for the processor to NT$37,000 ($1,160) from its original NT$35,000 ($1,100) launch price.
Midrange CPUs ($100 to $400)
This year's big story in middle-of-the-road CPUs can be nicknamed The Q Factor: In other words, quad-core. Last year, there was only one four-core processor out there to be had in this price range—Intel's Core 2 Quad Q6600 (it's aging, though still available)—but if you want to push your computer to the next performance level, you now have a wealth of options from both Intel and AMD that won't divest you of your personal wealth. To build solid computers for almost any purpose except pushing the envelope for pushing's sake, these CPUs are among the best choices out there.
Near the lower end of the price spectrum on the Intel side are the older 2.66GHz Core 2 Quad Q6700, and the newer, Penryn-based 2.5GHz Core 2 Quad Q9300. The Penryn model costs about the same ($266) and has a lower L2 cache (6MB as opposed to 8MB), but it runs at an FSB speed of 1,333MHz. If you have a few more bucks to spend, you can opt for a higher-level Penryn: the 2.66GHz Core 2 Quad Q9450, which also has a 1,333MHz FSB, but a 12MB L2 cache.
There are even more choices on the AMD side, with the Phenom X4 line. The processors in this family and price range all share the same L2 cache size of 2MB, but they differ in their clock speeds and prices. The Phenom 9550 is 2.2GHz, the Phenom 9650 is 2.3GHz, and the Phenom 9850 is 2.5GHz. (The 9850 also has the benefit of an unlocked multiplier for greater ease in overclocking.)
If you don't want to spend even that much money, of course, you can opt for high-end dual-core processors instead, in either AMD's Athlon X2 series or Intel's Core 2 Duo line. In neither case will you have to shell out more than $200. If you go with Intel, look for Wolfdale processors, which are based on the newer, 45-nanometer (nm) Penryn manufacturing process. These include the 3GHz Core 2 Duo E8400 and the 2.66GHz Core 2 Duo E8200.
AMD gives you a third option: three-core processors. Unsurprisingly, they offer performance (and price) positioned somewhere between dual- and quad-core CPUs; they're available for less than $200 and might make a sensible middle ground for an even more budget-priced machine. The Phenom X3 series contains the 2.1GHz 8450 and the 2.3GHz 8650 (both with 3.5MB of L2 cache), and the 2.4GHz 8750 (with a 3x512KB L2 cache).
Core Beliefs: Quad-Core vs. Dual-Core CPUs
The core is dead. Long live the cores!
Yes, if you're determined, you can still track down single-core processors (particularly in laptops). But, frankly, why bother? New advances in CPU technology have caused prices at the lower end of the performance scale to plummet, meaning you can now find two-core processors for less than $100, even less than $70—about the same you'd pay for single-core chips.
The difference in capabilities is worth it. Even if you're not running multithreaded software programs (such as video editors), having multiple processing cores on a single chip improves performance because Windows can run its background tasks on the second core, freeing the first core to run programs of your choice, unimpeded. (You'll notice this most when you are running multiple applications simultaneously.)
Obviously, the increase in power you'll notice with four cores as opposed to two is even more dramatic—assuming you're using apps that support all four cores, though there's still a relative lack of those on the market.
Even so, given the proliferation of multicore systems, we think it's time to retire the single-core CPU from serious consideration at checkout time. Let's jump feet first into the future—you'll be amazed at the difference multicore chips can make in terms of performance.
CPU Cache, Clock Speed, and Bus Explained
Once upon a time, a processor's clock speed might have been the most reliable indicator of performance, but these days, it's just one of many important factors to consider. It's only meaningful, in fact, when compared to other CPUs in the same series; a quad-core 2.5GHz Core 2 Quad Q9400 from Intel will trounce a 3GHz Core 2 Duo E8400 in many tasks, for example. Those multiple processing cores are more important than the 500MHz difference in clock speed.
Another important factor is a processor's L2 cache, which stores memory data and speeds up operation by making recently accessed data immediately available to the processor. Generally, the larger the L2 cache, the bigger the performance increase you can expect, at least with Intel CPUs that utilize one larger shared cache. AMD processors, on the other hand, give each core its own cache.
Front-side bus (FSB) speed is the rate at which an Intel processor communicates with the motherboard's memory controller. A high FSB speed boosts the performance of RAM-intensive operations, thus cutting the time it takes for data to move between the CPU and the memory controller. The upper limit of FSB speeds today on Intel's highest-end Core 2 Extreme processors is 1,600MHz, while older processors have FSB speeds of 800MHz, 1,066MHz, or 1,333MHz. Make sure your motherboard supports the FSB speed of the processor you want to buy, however, so you can avoid any potential performance bottlenecks.
An AMD CPU doesn't have an FSB—instead, the memory controller is located right on the chip, and the memory transfer takes place over the HyperTransport bus link between the processor and the memory.
