Benchmark Analysis
Overall, the benchmark results were up to our expectations, and the Phenom II X4 810 performed at about where we anticipated a 2.6 GHz, cache-stunted Phenom II core would. It did quite well against the mainstream Intel quad cores, and could be mentioned in the same breath as a Core 2 Quad Q9400. The Phenom II X3 720 is a far more interesting processor, as this was our first glimpse of a triple-core Phenom II, and at 2.8 GHz, it matches the X4 920 as the second highest clocked model.
With one less physical core, the X3 720 does suffer a bit in the high-end multi-threading tests, but its full 6MB of L3 cache and a higher clock speed help make up for it. In the gaming arena, where 2 cores is often enough, the Phenom II X3 720 regularly blew past the Phenom II X4 810 and performed very close to the level of a 2.8 GHz Phenom II X4. And that's not even mentioning that this is a Black Edition model, with an unlocked multiplier just primed for overclocking.
Overclocking
Although this is not a brand new core design, the AM3 revision of the Phenom II deserves close examination for overclocking potential. The Phenom II X4 810 is a standard locked model, and since Black Editions are available for similar prices, we're assuming the hardcore AMD crowd will go black and not go back. So that brings us to the Phenom II X3 720 BE, and its unlocked multiplier and 2.8 GHz default clock speed.
Our overclock testing used the standard reference configuration, supplemented by a powerful Thermalright Ultra 120 Extreme heatsink + 120mm fan. At the default 1.31V voltage, we got the Phenom II X3 720 as high as 3.3-3.4 GHz, which was similar to our previous results with the Phenom II X4 940. At the next increment of 1.4V, we managed to hit 3.5 and 3.6 GHz, but we raised it to 1.43V in order to reach 3.7 GHz.
Unfortunately, 3.8 GHz would not load Vista until we raised the voltage levels to 1.46V-1.47V. But that was as far as we could take this particular CPU and even after raising voltages to 1.5V and some extensive fiddling with the CPU, NB, chipset, HT, and even DRAM voltage settings, the CPU would not remain stable at 3.9 GHz.
This was the same upper limit we experienced with the Phenom II X4 940 BE, but overclocking the Phenom II X3 720 BE was much easier at the mid-range speeds. We reached 3.6 GHz without even trying, and even 3.7 and 3.8 GHz were not that bad, but we hit a serious wall at 3.9 GHz, like the chip just slammed the OC door in our face. But for those looking to easily move to a 3.5-3.6 GHz triple-core, the Phenom II X3 720 BE is a great bet.
Total System Power Consumption Testing
In order to measure power consumption, we took each of the AMD and Intel reference systems, ran the outlet through a Power Analyzer, and then compiled total system (minus display) consumption figures (in Watts) for Idle and Load scenarios. In order to keep the systems and results consistent, we used the same configuration for the AMD and Intel processors as listed on the Test Systems page.
The first test measures the total system power usage when the AMD and Intel processors are set to power-saving mode. For AMD, this means enabling Cool'n'Quiet, while for Intel we need to activate Enhanced SpeedStep. The test was performed after the operating system has loaded, and all of the various software and hardware components have initialized and we hit a consistent power reading.
This first set of power usage results give us another amazing example of the 45nm Phenom II architecture, and what an improvement it is over the first-generation Phenom core. With power savings enabled, the Phenom II X3 720 system finished with the lowest consumption total, and the Phenom II X4 810 placed third.
The second test changes the operating conditions from Idle to Load, and the SANDRA Multimedia CPU benchmark pushes processor usage to 100%, while ensuring that no extraneous hard drive or peripheral activity artificially ramps up the power consumption rates. The results using SANDRA are also incredibly consistent, with the wattage numbers remaining stable through the entire test.
At full CPU load, there is a small shift in the chart, as the Core 2 Duo E8500 takes over the top spot, which is hardly surprising given that it's a dual core. The Phenom II X3 720 and X4 810 are not far behind and place second and third respectively. AMD dropped both of these to the 95W threshold, compared to 125W for the Phenom II X4 920 and 940, and it's borne out in the consumption totals.
Please keep in mind that these numbers relate to total system power consumption, of which the CPU is only one part. In evaluations like this, relative placing is sometimes more important than the base numbers, which can change based on the platform and peripheral mix.
