Although the AMD Phenom processor series got off to a rocky start when released on November 19th 2007, it has slowly come good over the years. The original Phenom 9500 and 9600 processors were plagued by a bug, which caused AMD to hold off on releasing any more B2 stepping Phenom processors.

Thankfully, some 4 months later, AMD was able to push out the B3 stepping and with it came a heard of new and improved Phenom processors. Still, in terms of performance, they were not competitive with the Core 2 Quad range, and therefore AMD slashed prices aggressively.

By July 2008 the Phenom series had reached its end, stopping at the Phenom X4 9950 Black Edition, which was clocked at a dismal 2.60GHz. Although the Phenom processors were showing quite good clock for clock performance against the Core 2 Quad series, with their fastest processor clocked at just 2.60GHz it could not compete with the likes of the Core 2 Quad Q9550 at 2.80GHz and the Q9650 at 3.0GHz.

Finally, after a great deal of waiting, AMD managed to get the Phenom to a point where it really should have been over a year ago. With the release of the Phenom II architecture came a real competitor for the Core 2 Quad series. The Phenom II X4 920 and 940 got the ball rolling in January 2009, and with the recent arrival of the Phenom II X4 955 Black Edition, things are really starting to look promising for AMD.

The Phenom II X4 955 Black Edition is currently priced at just $245 US, and at that price Intel really has nothing that can deliver the same level of performance. Those looking to spend even less on a high-performance AMD “Black Edition” processor have the triple-core Phenom II X3 720 as an alternative at just $140 US.

However we now have an even cheaper Phenom II series featuring just two cores. The new Phenom II X2 series is the ideal competitor for Intel’s budget dual-core processors, and with the flagship model priced at just $100 US, we are pretty excited to show you what it can do. The Phenom II X2 550 Black Edition comes clocked at an impressive 3.10GHz, and still features the huge 6MB L3 cache.

In fact, if you look at the Phenom II X2 on paper and compare it to the Phenom II X4 series, you will notice that other than the difference in the number of cores that they posses, they are otherwise identical. This is impressive, as you have to wonder how AMD are able to sell their latest and greatest processor architecture for just $100 US.

There is a simple reason for why AMD are able to do this, and in fact why they do it in the first place. Like the triple-core Phenom II X3, many of the new Phenom II X2’s will be defective Phenom II X4 processors. Basically, if there is a problem with one of the four cores on a Phenom II X4 processor that cause it to fail quality control, AMD cannot sell it.

However, they can disable this core, eliminating any potential problems that it may cause, creating a triple-core processor. Rather than throw the processor away, AMD are able to sell them as Phenom II X3 and now Phenom II X2 processors. This is not an unusual practice, and many companies will do similar things with their products, so we do not have a problem with it.

Ultimately what this means is that consumers can get their hands of Phenom II technology for less than half the price with the Phenom II X2 550. Keeping all this in mind, not all Phenom II X2 processors will feature one of two defective cores, AMD may simply disable the other two just so that they can meet the demand, and given what we are about to show you, we believe that demand will be very high...

Intel Test System Specs - Intel Core 2 Duo E7400 (2.80GHz) - x2 2GB DDR2-1066 G.Skill (CAS 5-5-5-15) - ASUS P5E Deluxe (Intel X48) - OCZ GameXStream (700 watt) - Seagate 500GB 7200-RPM (Serial ATA300) - ASUS GeForce GTX 285 (1GB) Software - Microsoft Windows Vista Ultimate SP1 (64-bit) - Nvidia Forceware 185.85

AMD Test System Specs - AMD Phenom II X4 910 (AM2+) - AMD Phenom II X2 550 (AM3) - AMD Phenom X4 9950 (AM2+) - x2 2GB DDR2-1066 G.Skill (CAS 5-5-5-15) - x2 2GB DDR3-1333 G.Skill (CAS 7-7-7-17) - ASUS M4A79T Deluxe (AMD 790FX) - ASUS M3A79T Deluxe (AMD 790FX) - OCZ GameXStream (700 watt) - Seagate 500GB 7200-RPM (Serial ATA300) - ASUS GeForce GTX 285 (1GB) Software - Microsoft Windows Vista Ultimate SP1 (64-bit) - Nvidia Forceware 185.85

The Phenom II X2 550 was found to be 6.5% faster than the Core 2 Duo E7400 in the multi-thread rendering test, while it was also 5% faster in the single thread test. That said, the Phenom II X2 550 is clocked 7% higher than the E7400, so on a clock for clock basis they would deliver about the same performance in the CINEBENCH processor test.

The AMD processors have never performed very well in the CINEBENCH R10 OpenGL rendering test, and although the Phenom II X2 550 was faster than its lower clocked quad-core part, it was still 7% slower than the Core 2 Duo E7400. This is an interesting result and could spell trouble for the Phenom II X2 550 come time to benchmark it in games.

Thanks to the onboard memory controller, the Phenom II X2 550 is significantly more efficient than the Core 2 Duo E7400 in terms of memory bandwidth performance. This is evident when running the SiSoftware Sandra 2009 memory bandwidth test, as the Phenom II X2 550 has 80% more bandwidth at its disposal. Please note that this bandwidth is achieved using either DDR3-1333 or DDR3-1066 memory, and the use of DDR3 memory gives the Phenom II X2 550 no real advantage over the Core 2 Duo E7400.

The Phenom II X2 550 was able to match the Core 2 Duo E7400 processor in the SiSoftware Sandra 2009 multi-media test.

The multi-core efficiency test went the way of the Core 2 Duo E7400 processor. SiSoftware Sandra 2009 is reporting that the E7400 has twice as much bandwidth available when talking between cores when compared to the Phenom II X2 550. It would appear that core bandwidth is a weakness of the Phenom II architecture.

EVEREST Ultimate Edition has also been used to measure the bandwidth between the CPU and the RAM. As you can see, the results are much different to those reported by SiSoftware Sandra 2009, as the Core 2 Duo E7400 bandwidth is much healthier when compared to the Phenom II X2 550. Nevertheless, the Phenom II X2 550 still showed better performance thanks to the on-die memory controller.

ScienceMark appears to favor the AMD processors, and while the Core 2 Duo E7400 did deliver similar performance to the quad-core Phenom X4 9950, the Phenom II X2 550 was 21% faster. Although this benchmark does like the AMD processors, it does not appear to be quad-core optimized.

WinRAR is quad-core optimized and therefore the Phenom X4 9950 and Phenom II X4 910 do exceptionally well. The Phenom II X2 550 on the other hand was also very impressive, delivering 23.5% more performance than the Core 2 Duo E7400 in the single thread test, and 27.5% more in the multi-thread test.

Super PI is another benchmark that has never been an AMD favorite, and the Phenom II X2 550 does little to change this. The Core 2 Duo E7400 made the 2MB calculation 20% faster than the Phenom II X2 550, which is obviously quite a large margin.

The Phenom II X2 550 was not all that impressive in Microsoft Excel 2007, as both scenarios placed it well behind the Core 2 Duo E7400. The Phenom II X2 550 took 36% longer to complete the first task, and 24% longer for the second task. These are disappointing results given how well the Phenom II X2 550 has looked in past tests.

While the Phenom II X2 550 may have been disappointing in Excel, the gaming performance looks to be very good. First up we tested with Unreal Tournament 3, and at 1920x1200 the Phenom II X2 550 was 19% faster than the Core 2 Duo E7400.

Although Crysis Warhead is extremely GPU bound, the Phenom II X2 550 was able to render a few more frames per second when compared to the Core 2 Duo E7400.

Then finally when testing with Far Cry 2, the Phenom II X2 550 was found to be 9% faster than the Core 2 Duo E7400 at 1920x1200.

This is where the Phenom II X2 550 is most impressive, as not only for the most part was it faster than the Core 2 Duo E7400, it was also more efficient, using less power. While under full load and at idle, the Phenom II X2 550 used around 10% less power than the E7400.

Overclocking the Phenom II X2 550 increased the WinRAR multi-thread performance by 9%, while the single thread performance hit 900KB/s.

The Phenom II X2 550 was 26.5% faster in the CINEBENCH multi-thread rendering test once overclocked, making it considerably faster than the standard Core 2 Duo E7400 processor.

Overclocking the Phenom II X2 550 boosted the Unreal Tournament 3 performance at 1920x1200 by 11%, which equated to 14fps.

Overclocking the Phenom II X2 550 did hurt its operating efficiency, as power consumption levels drastically increased. Still, when placed under load it used the same amount of power as the Phenom II X4 910. That said, the idle consumption levels were quite high, as it now used around 40% more power when inactive.

For the most part the Phenom II X2 550 proved to be faster than the Core 2 Duo E7400, which costs 20% more at $120 US. Although the Phenom II X2 550 did show one or two weaknesses, it was the gaming performance that impressed us the most. Not only was this new AMD processor faster than the E7400 in all three tested games, it was also comparable to the Phenom II X4 910.

This is exciting news as the Phenom II X2 550 at $100 US could be paired with the Radeon HD 4770, which also costs $100 US, making for what could possibly be the cheapest and most powerful gaming platform ever. The ATI Radeon HD 4770 blew us away with its phenomenal performance, particularly when placed in Crossfire mode.

The Phenom II X2 550 clocked at 3.10GHz has enough horse power to accelerate not one but two Radeon HD 4770 graphics cards to full speed if need be. Imagine being able to play a game such as Call of Duty World at War for example, in all its glory at resolutions up to 2560x1600 on a system that costs less than $500 US.

Back when we tested the Radeon HD 4770 graphics cards in Crossfire mode, they delivered 88fps at 1920x1200 and 55fps at 2560x1600 in Call of Duty World at War. Additionally, a single Radeon HD 4770 managed 61fps. Based on current pricing, we believe users can build a Phenom II X2 550 gaming system using the Radeon HD 4770 with 4GB of DDR2 memory on a decent AM2+ motherboard, for around $300 US, which is simply amazing!

The other great news is because these components use such a small amount of power when compared to other gaming related hardware, they will make for a cool and quiet computer. Furthermore, the Phenom II X2 550 appears to be the ultimate upgrade solution for those looking to build a brand new computer from the ground up, or simply those looking to give their old AM2 rig a little more juice.

This is because the Phenom II X2 550 can be installed on a range of AMD platforms, starting with their latest AM3 socket, to the older AM2+, and even AM2 sockets. Additionally, this also means that the Phenom II X2 range will support DDR2 and DDR3 memory.

There is a lot to like about the new Phenom II X2 550 Black Edition processor, and while this includes performance, power consumption, price, and flexibility, there is something else... overclocking performance! Although we had very little time to play with the Phenom II X2 550 before getting this review online, we were able to reach a completely stable overclock of 3.90GHz by simply tweaking the clock multiplier and core voltage.

The 25% frequency boost came all too easy, and with the aid of an upgraded air-cooler (Thermolab Baram) the temperatures were incredibly low. Therefore, we believe by throwing more voltage at the processor, it should be able to crack the 4.0GHz barrier. Overall we really like the new Phenom II X2 550 processor, as it is an excellent alternative to the Intel Core 2 Duo series, and with a recommended retail price of just $100, it’s a bargain.

Reviewed By Steven Walton