Clock Rate Versus Core Count On Core i7-980X

Despite the Core i7-980X's impressive performance and surprisingly high efficiency, we were disappointed that Intel didn't get more aggressive with Turbo Boost, the feature that increases core clock speeds within a given thermal envelope when more performance is needed. Fortunately, six-core "Gulftown" can overclock like a champ. The question is whether manually forcing this extra performance causes a big hit in the CPU's efficiency or not. And whether inside or beyond Turbo Boost's limits, is there a speed setting where the Core i7-980X displays optimal efficiency? That's what we're here to find out.

A perfect processor offers more than substantial multi-core performance. The new Core i7-980X delivers copious alacrity in applications that can take advantage of its six cores (or as many as 12 logical threads with Hyper-Threading enabled). However, this isn’t the fastest Intel processor when it comes to raw frequency. Turbo Boost allows the 3.33 GHz Gulftown to reach 3.60 GHz on a single core, but a $196 Core i5-66x offers similar speeds (and as a result, theoretically comparable single-thread performance). The Core i5-670 is even faster at 3.73 GHz and can technically overtake Intel’s $1,000 six-core flagship when it comes to single-threaded workloads.

Of course, there's some room for debate here, since the Extreme Edition chip's 12MB L3 cache can be allocated to a single task. So too can the Core i5's 4MB cache, but there's quite a bit of difference there. Nevertheless, in most single-threaded apps, clock rate is what determines performance.

We wanted to make a handful of alterations and squeeze more performance from of the six-core beast. Ultimately, Gulftown is a 32 nm processor, just like the Clarkdale-based Core i5s, which have shown amazing overclocking capabilities. Even with six cores, it should be possible to accelerate the i7-980X up to where it easily beats Intel's other offerings without consuming excessive power.

Platform: Intel DX58SO

Intel’s 5000 BIOS version supports the six-core Gulftown processor and offers very granular settings for the number of speed steppings available to various core counts under Turbo Boost.