Core i3 takes on Athlon II ...and everything else, including a Pentium 4

Coming up with a way to characterize a major comparison of desktop processors like this one isn't always easy. Since our initial review of Intel's Clarkdale processors, the desktop CPU market has shifted in a number of ways both big and small. For one, Clarkdale CPUs have proliferated everywhere, and we've gotten our hands on one model, the Core i3-530, that promises to be a much better value than the relatively high-end Core i5-661 that we first reviewed. To counter, AMD has introduced five new value-oriented CPUs, ranging from two cores to four, including the Athlon II X4 635, a potent value quad-core priced directly opposite the Core i3-530.
Naturally, we've tested these two direct competitors against one another, considered their power consumption, and plumbed the depths of their overclocking potential. But we've also had Damage Labs churning away around the clock to expand our CPU results substantially. We now have test results for processors priced as low as $74 and as much as a grand. Not only that, but we've looked back in time by testing a pair of older CPUs—including the always interesting Pentium 4 670 at 3.8GHz—to give potential upgraders a sense of what they might have to gain. Join us as we navigate a sea of test results and consider the best values available in today's desktop processors.

The Clarkdale continuum
At a price of just $113, the Core i3-530 is much more reasonably priced for a dual-core processor than the Core i5-661 we considered in our first Clarkdale review. Yet because it's a Clarkdale processor, the Core i3-530 has inherited much of the goodness from its elder siblings in the Core i7 line, including the ability to track and execute two threads per processor core (known as Hyper-Threading in Intel marketing parlance), an integrated DDR3 memory controller, and a CPU microarchitecture that does an awful lot of work in every clock cycle. In truth, Clarkdale processors are rather unique, because they're really two chips in one package: a 32-nm dual-core Westmere processor and a second, 45-nm chip that houses a memory controller, an integrated graphics processor (IGP), and PCI Express logic.

Pentium E6500, Core i3-530, and Core i5-661

Clarkdale CPUs will plug into LGA1155 or LGA1156-style sockets, but you'll need an LGA1155 motherboard to take advantage of the integrated graphics. Here's a look at how the i3-530 fits into the broader Clarkdale lineup:

Model	Cores	Threads	Base core clock speed	Peak Turbo clock speed	L3 cache size	IGP speed	TDP	Price
Pentium G6950	2	2	2.8 GHz	-	3MB	533 MHz	73W	$87
Core i3-530	2	4	2.93 GHz	-	4MB	733 MHz	73W	$113
Core i3-540	2	4	3.06 GHz	-	4MB	733 MHz	73W	$133
Core i5-650	2	4	3.20 GHz	3.46 GHz	4MB	733 MHz	73W	$176
Core i5-660	2	4	3.33 GHz	3.60 GHz	4MB	733 MHz	73W	$196
Core i5-661	2	4	3.33 GHz	3.60 GHz	4MB	900 MHz	87W	$196
Core i5-670	2	4	3.46 GHz	3.73 GHz	4MB	733 MHz	73W	$284

One perk Intel has stripped out of the relatively inexpensive i3-530 is the Turbo Boost feature that raises clock speeds opportunistically when thermal headroom is available. Fortunately, the i3-530's base frequency of 2.93GHz is pretty respectable all by itself. The i3-530 has the same 73W thermal design power rating as the rest of the lineup, except for the weirdo i5-661, whose higher-clocked IGP contributes to its 87W TDP. We've tested both the i3-530 and the i5-661, and through the magic of underclocking, we have simulated the Core i3-540, as well.
Of course, Intel's product lineup extends well beyond Clarkdale, to the Core i5-700- and Core i7-800-series quad-core Lynnfield processors and into the beefy Core i7-900-series CPUs with triple-channel memory controllers.

Model	Cores	Threads	Base core clock speed	Peak Turbo clock speed	L3 cache size	Memory channels	TDP	Price
Core i5-750	4	4	2.66 GHz	3.20 GHz	8MB	2	95W	$196
Core i7-860	4	8	2.80 GHz	3.46 GHz	8MB	2	95W	$284
Core i7-870	4	8	2.93 GHz	3.60 GHz	8MB	2	95W	$562
Core i7-920	4	8	2.66 GHz	2.93 GHz	8MB	3	130W	$284
Core i7-960	4	8	3.20 GHz	3.46 GHz	8MB	3	130W	$562
Core i7-975 Extreme	4	8	3.33 GHz	3.60 GHz	8MB	3	130W	$999

We've included representatives from nearly every rung of the ladder, including one relative newcomer, the Core i7-960. At $562, the Core i7-960 costs just over half what the thousand-dollar Core i7-975 Extreme does, yet the difference between them is only 133MHz. (Well, the Core i7-975 Extreme earns its extremeness by offering an unlocked upper multiplier for the overclocking crowd, too. But you have to ask yourself: how much is an unlocked multiplier worth?) The Core i7-960 replaces the i7-950 at the same price point, a reshuffling no doubt prompted by the introduction of the very potent Core i7-870 at the same price on another socket.