Intel's 45nm Dual-Core E8500: The Best Just Got Betterby Kris Boughton on March 5, 2008 3:00 AM EST
- Posted in
So Dual-Cores are no Longer Extreme?
It may be hard to believe, but the quad-core concept just celebrated its first birthday. Launched in late 2006, this anniversary also signifies the introduction of a rather significant adjustment to Intel's eternally-evolving marketing strategy. For the first time ever, Intel has decided not to produce a dual-core Extreme Edition variant of their leading quad-core product offering. That means there are currently no plans to manufacture a 45nm dual-core CPU featuring an unlocked multiplier (or as Intel likes to put it, with "overspeed protection removed"). Until now, this made choosing the right processor easy: those that lacked the means (or the need) for a quad-core could feel content in knowing they would not be expected give up having an unlocked multiplier should they decide to go with the dual-core in lieu of quad. Now, anyone that wants to enjoy the operational freedom that comes with having a fully adjustable multiplier with a 45nm processor will have to pony-up the dough for a QX9650 (or QX9770) or go without.
We recognize this change for what it really is - a bold move when it comes to fulfilling the needs of enthusiasts worldwide, considering how a vast majority of today's games and applications still favor systems with fewer high-speed cores over those with more cores at lower frequencies. Intel's decision to supply processors with unlocked multipliers under an "Extreme Edition" branding became an essential ingredient in the creation of all future roadmaps. Eventually these unique processors became the basis for a new class of computing platforms, one that embodied a shift in marketing philosophy. Rather than focus solely on serving the large OEMs, Intel also recognized the direct importance of the enthusiast community. We could argue that when it came to winning the admiration and approval of overclockers, enthusiasts, and power users alike, no other single common product change could have garnered the same overwhelming success.
Our love affair with the quad-core began not too long ago, starting with the release of Intel's QX6700 Extreme Edition processor. Ever since then Intel has been aggressive in their campaign to promote these processors to users that demand unrivaled performance and the absolute maximum amount of jaw-dropping, raw processing power possible from a single-socket desktop solution. Quickly following their 2.66GHz quad-core offering was the QX6800 processor, a revolutionary release in its own right in that it marked the first time users could purchase a processor with four cores that operated at the same frequency as the current top dual-core bin - at the time the 2.93GHz X6800. From there only a small default FSB speed bump from 266Mhz (1066 quad-pump) to 333Mhz (1333 quad-pumped) and a stepping change from B3 to G0 was all that was needed to justify the creation of the QX6850, which ran at a slightly higher speed of 3.0Ghz (9x333). Again, the X6850 matched the QX6850 in every way but one, that being that it had two fewer cores.
Writing multithreaded code that makes efficient use of four or more cores is a daunting task - to date few applications and even fewer game developers are able to boast of this accomplishment. Given this, is it that hard to admit that perhaps we've all been a little guilty of demanding too much, too soon from our favorite software vendors? It should not be surprising then to learn then that many of today's ultimate gaming machines make use of "lesser" dual-core CPUs in place of their quad-core counterparts. With most titles able to take advantage of only two cores at a time, optimum gaming performance (read: maximum FPS) is often achieved by running a dual-core CPU at a greater frequency than is attainable using even the best quad-core processors.
Because dual-cores can often be coaxed to run at a higher, final stable speed then quad-core CPUs - which also consume significantly more power - most modern games have been engineered to make use of no more than two threads simultaneously executing in parallel. These games thus benefit from the additional overclocking headroom of dual-core CPUs. Meanwhile, in the case of the quad-core processor, approximately half of the processing resources sit idle while the code executes on any two of the four slower cores.
If you're not an overclocker, aside from the obvious processor count increase from two to four cores, there is little difference between Intel's top-end dual-core E8500 and their QX9650 Extreme Edition quad-core CPU. Each is fabricated based on exactly the same underlying 45nm, second-generation Core 2 architecture. Both interface with their host motherboard's MCH at an equivalent quad-pumped FSB speed of 1333MHz. And technically speaking, on a by-core basis, each must contend for the same amount of shared Level 2 cache (6MB per die). The only real difference is their core operating frequencies - the E8500 at 3.16GHz (9.5x333) and the QX9650 at 3.00Ghz (9x333). Because of the raw speed advantage, if the target application or game only makes use of two cores then the E8500 ends up being the better choice.
This isn't to say that the quad-core CPU is left without the existence of a proper application - far from it. Programs that heavily rely on the impressive parallel processing capabilities of a quad-core processor can realize up to nearly double the per-clock performance. This is especially true of tasks that lend themselves to the use of multiple program instances. For example, consider an encoding program that makes use of only two cores. Running two instances, and simultaneously encoding two files, would effectively load all four cores. Of course, this assumes there is a work queue in which the next available job can be drawn from, without which no benefit could be realized. There are certainly applications where more cores is almost always better; whether you use those applications on a regular basis is the real question.