The first is price. AMD has the upper hand here. Although its Phenom II X4 940 is priced fairly close to Intel’s Core i7 920, 790GX-based motherboards cost in the neighborhood of $150, while high-end X58 platforms generally tend toward $300 (although we’ve recommended a $250 model here). DDR3 memory is still significantly more expensive than DDR2. Populating three channels, the more modern technology is going to bear a notable premium over two channels of the more mainstream type. In all, the Phenom II machine costs about $250 less to build than our i7 box did, while arming the AMD platform with a better aftermarket cooler would have shaved $50 or so from its advantage.

Next is performance. Intel maintains its advantage in this one, even with both configurations overclocked. We very effortlessly achieved a 3.8 GHz overclock on the i7 920 by bumping its Bclk up to 190 MHz and keeping all other settings in place. Knowing that our own German lab was able to reach 3.8 GHz stably on air (and AMD’s lab team said to expect frequencies up to 3.9 GHz at 1.55 V), we pushed our X4 940 extremely hard. While we were able to boot at up to 3.8 GHz, benchmarks wouldn’t finish consistently until we had dropped down to 3.64 GHz—and that was still at 1.6 V. Anything less and even that speed wasn’t 100% solid. Given the speeds we were able to achieve, Intel’s entry-level Core i7 walked away from AMD’s fastest Phenom II in all but one test.

Third, you have power. We’re giving this one to AMD, as well. At idle—where you’ll spend most of your time—the overclocked Phenom II spins down to 800 MHz and yields some impressive power figures. Once it shoots back up to 3.64 GHz, it’s sucking down more juice than Intel’s 3.8 GHz Core i7. However, we anticipate that most enthusiasts aren’t going to peg their chips at redline very often.

When stressed, Air-cooled Phenom 9850 will reach 60+ Celsius, but once you stop all the nasty applications it idles all the way to really mild 28 – 35 Celsius. The only thing you need to do is the enable Cool and Quiet on your motherboard and set the energy settings in Windows to energy efficient. In Idle mode Cool’n Quiet downlocks the CPU to 1250MHz with 6.25 multiplier times 200 MHz buss speed. This actually means when you surf the net and read your word documents, that most of us do most of the time, the Phenom 9850 will go down to below 40 Celsius; while in games it can easily get back to the low sixties.

What are the limits for overclocking an AMD 5000+ Black Edition on an Asus M2R32-MVP motherboard with OCZ Reaper PC-9200 memory powered by a 1200 Watt SilverStone power supply? AMD overclock contest entrant Deux takes us through each of the components and pushes them to their limits to answer this question. He describes each of the components, their pros and cons, his overclocking techniques and results of the overclock in this contest entry.