Review: AMD's Phenom Quad-Core 'Black Edition'

Previously referred to as B3, the Quad-Core X4 9550, 9750, and 9850 (collectively being called the 50-series) amount to a new revision of the CPU in which the TLB erratum that plagued the last round of Phenoms is no longer present.

The Test Center set up a test bed and ran some tests on the 2.5 GHz X4 9850 Black Edition, so named because it is the only version with an unlocked multiplier.

Our test system included a Gigabyte MA790FX-DQ6 motherboard installed in an Antec case with an Ultra 3X 1000 watt power supply, a 160Gb SATA HDD, running Windows Vista Ultimate with SP1.

Our original testing included the benchmarking software, Geekbench 2. With a total score of 4382, the Black Edition is right where it should be in performance. But since the Black Edition is the only one in the lineup with an unlocked multiplier, we decided to take our evaluation unit for a ride.

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At this point, we need to point out that neither AMD (nor the Test Center, for that matter) endorses or recommends overclocking your processor. Besides voiding the warranty, it can do serious and/or permanent damage to the CPU (more on that in a minute) and/or motherboard, as well as destabilize a system and shorten the life of all components. In addition, if you still decide to overclock, it is suggested that the voltage be increased as you push the chip.

First, we ran Overdrive's benchmarking utility and got a score of 7294. This was with the multiplier set at the factory default of 12.5x (times the 200 MHz BUS speed equals 2.5 GHz). Once the overclocking began, at 2.6 GHz the score reached 7505 on Overdrive. We continued pushing the limits until we reached a multiplier of 15x which had the CPU running at an even 3.0 GHz. At this setting, the Overdrive benchmark score was a remarkable 8851.

Soon after our benchmark test was completed, our system froze and, after shutting down, would not reboot. A quick swap of the processor confirmed that the Black Edition had fried during testing. (Luckily, there was no other noticeable fallout beyond the CPU.) On a system that was designed specifically with overclocking in mind, the Black Edition X4 9850 will probably fare better than ours did . . . but don't say we didn't warn you.

The 50-series of processors are replacing their 00-series predecessors and AMD states that they will perform the same clock-for-clock as older revision B2 processors operating in a platform not implementing a TLB fix. For example, the 2.2GHz Phenom 9550 processor will replace the Phenom 9500 (B2) processor. The series is socket-compatible with the AM2 which makes them a good upgrade option without having to stock new motherboards.

One important note: System builders should be aware that, because of the newness of the 50-series Phenoms, most motherboards will need to have their BIOS flashed to the latest version before they will recognize the CPU.

AMD has set pricing on the Phenom 50 Series from between $195 to $235 per 1,000 units and they are available now through the channel.


Further post-test examination of the system, after the 9850 locked and refused to reboot in the test bed, turned up a problem upstream from the processor that appears to have impacted the CPU's performance.

The Gigabyte motherboard supplied by AMD for examination of the Phenom Black Edition does not support the CPU out of the box; an older, AMD CPU was needed to download and install an up-to-date bios, and then flash it to the motherboard.

After the 9850 locked, stopped working and refused to reboot during the overclocking exercise, testers decided to go back to the drawing board. Steps were repeated, including installing an older CPU to re-download the bios, again flash it to the board, and attempt a reboot.

It worked.

Overclocking exercises were again undertaken but testing was ceased before any further incidents.