AMD Refreshes The Dragon

As with past AMD CPUs, the X4 indicates quad core, and the Black Edition label signifies an unlocked multiplier. Both processors have 64K of L1 instruction and 64K of L1 data cache per core (512 KB total L1 per processor), 512 KB of L2 data cache per core (2 MB total L2 per processor) and 6 MB (shared) of L3 cache.

When originally released, the first Phenom II processors, along with the ATI Radeon HD 4800 series graphics (AMD acquired ATI in 2006), AMD 7-series chipsets and AMD software, were all part of the platform AMD code-named "Dragon." The latest CPUs are part of the next generation of this platform, now called "Dragon Refresh." Besides the new processors, Dragon Refresh includes the new ATI Radeon HD 4890 GPU, AMD 700-series chipset-based motherboards and AMD OverDrive 3.0.

The Test Center evaluated the Black Edition X4 955 in a Gigabyte GA-MA790FXT-UD5P motherboard, installed in an NZXT Tempest chassis, with an ATI HD 4650 graphics card and an Antec TruePower Quattro 850 power supply. Using 4 GB of Corsair CM3X2G1600C9DHX DDR3 RAM, our operating system was Windows Vista Ultimate with all current patches, drivers and updates installed.

When booting into Microsoft Windows, reviewers were pleased to see that the system had a bit of noticeable speed to it. When testing with Primate Labs' benchmarking software Geekbench2, the default BIOS settings yielded a nice score of 5,960. We weren't done yet though. Using the latest version of AMD's OverDrive software, also launched Thursday, test scores would continue to rise.

OverDrive has historically been an easy way for novices and enthusiasts alike to overclock AMD processors. With version 3.0, the company has added new features that also make it easier to fine tune some settings. With another acronym, BEMP (Black Edition Memory Profiles), AMD has worked with memory manufacturers to create a database of specifications for certain high-frequency DDR3 modules. When using a motherboard with a BIOS that supports it, OverDrive 3.0 can use BEMP to look up frequency and latency settings and automatically set the parameters within the BIOS.

Just by using BEMP, our Geekbench2 score jumped to 6,114 but, this being a Black Edition, we decided to push the CPU a little and do some overclocking. Using only stock heat sink and fan cooling, reviewers slowly increased the processor's multiplier and voltage levels, finally reaching a surprising overall speed of 4.0GHz -- almost a full GHz above its out-of-the-box frequency. At this speed, our system's Geekbench2 score was 7,434.

Other new additions to OverDrive are Smart Profiles, which allow users to create (or use preconfigured) profiles that set parameters on a per-application basis. One good example of this is with games that are only dual threaded. With Smart Profiles, it is now possible to devote more processing speed to those two cores while reducing speed to the cores that are underutilized.

Admittedly, the X4 955 is still no match for Intel's current high-end CPU, the Core i7-965 Extreme, but its benchmarking scores come a lot closer than we would have expected. Considering the Core i7 Extreme is priced near $1,000, AMD's latest processors are a great value at $225 and $245 for the X4 945 and Black Edition X4 955, respectively.

Additionally, as with previous AMD chips, the socket AM3 CPU can still be used in socket AM2+ motherboards. This will make it more appealing to those with compatible boards looking for a relatively inexpensive upgrade.

And for everyone who may be concerned about the previous X4 940 losing its Black Edition status, an AMD spokesperson assures us that it will remain available in its unlocked form "for a period of time," although AMD wouldn't say how long that would be.

Overall, the Phenom II X4 955 Black Edition, along with OverDrive 3.0, is a powerful and stable processor at a very reasonable price. Reviewers were pleasantly surprised at the performance we saw and look forward to what the competition between the two CPU powerhouses brings next.