AMD Phenom II X2 550 Black Edition CPU

Manufacturer: AMD
UK Price (as reviewed): £71.86 (inc. VAT)
US Price (as reviewed): $102.99 (ex. Tax)

It's probably unnecessary to remind you that AMD has had very few successful "firsts" when it comes to its Phenom line. The latest Phenom II X2 550 Black Edition is, thankfully (or should that be "finally"?), the exception to the rule. It's the first dual-core Phenom II chip - and its actually pretty damn good!

As it's a Phenom II, it's a dual-core of 45nm origins, and is very similar to its bigger triple-core (X3) and quad-core (X4) brothers, only with two cores disabled. This means that with special motherboards, there's the possibility of unlocking the extra cores, although there's no guarantee that they'll work.

The 45nm K10.5 design used by the X2 550 BE features a huge 8MB of common L3 cache - more than enough to act as a snoop filter for just two cores - as well as DDR3 and DDR2 support. Supported memory speeds are faster than the Athlon II: 1,066MHz for DDR2 and 1,333-1,600MHz for DDR3. Another advantage is that this is a Black Edition product - so the multiplier is unlocked for easy overclocking.

It comes clocked at 3.1GHz, and with effectively a DDR3 memory channel per core (in un-ganged mode), there's not only oodles of cache, but also tons of fast memory access too.

• Clock Frequency: 3.1GHz, 200MHz x 15.5
  
• Core Count: Two physical
  
• L1 Cache: 64KB data and 64KB instruction per core (256KB in total)
  
• L2 Cache: 512KB exclusive data cache per core (1MB in total)
  
• L3 Cache: 8MB L3 inclusive cache
  
• Fabrication Process: 45nm DSL SOI (silicon-on-insulator) technology
  
• Packaging: Socket AM3 (Socket 938)
  
• Memory support: DDR2/DDR3
  
• Thermal Design Power (TDP): 85W
  
• Transistors: ~758 million
  
• Die Size: 258mm²

All this will set you back just over £70; in terms of its Intel competition, this situates it between the Core 2 Duo E6300 at £64, and the pricier E7400 at £85. It's not just CPU price that you need to look at when making a buying decision though: the cost of the whole platform (i.e. motherboard, CPU and memory) is crucial. In this respect, the X2 550 BE does rather well. Pair it with an MSI 770-CD45 motherboard and 4GB of low latency DDR3-1333 and it costs just £189. However, for an Intel Core 2 Duo E7400, Gigabyte GA-EP45-UD3R and 4GB of DDR2-1066 (it's £2 more than 800MHz), you'll need to shell out £224 - £35 difference.

Even if you choose the E6300 instead, the total system is still £15 more expensive. It doesn't sound like much, but it's halfway to a good CPU cooler such as the Titan Ferinr. The AMD setup should have more legs too - AM3 is in its infancy, with an upgrade to triple- or quad-core available, whereas LGA775 is at the end of its life. That said, cheap Q6600s could be flooding the market soon as upgrade cycles come around. All this is worth keeping in mind as we take a look at how well the X2 550 BE performs

Power Consumption

For all of the performance tests on the previous few pages, we disable all power saving technology in order to give us a consistent set of results, and also to obtain best-case performance numbers - technologies such as Intel's SpeedStep might only take microseconds to kick in, but that can make all the difference in some tests. However, for the power consumption tests we re-enable everything but Intel's Turbo Boost in order to get a real-world power draw.

Idle Power Consumption

For this test, we leave the PC doing nothing but displaying the Windows Vista desktop (with Aero enabled) for a few minutes and record the wattage drawn from the wall via a power meter.

Final Thoughts:

The Phenom II X2 550 Black Edition is what the II X2 250 should have been. In fact, there's very little reason to buy an old K8, or even K10 cored CPU now the Athlon II X2 250 and Phenom II X2 550 are available (unless, that is, you have a specific need for an ultra low power 45W 5050e).

The Phenom II X2 offers plenty of performance and potential for simple and advanced overclocking for enthusiasts to have fun with. It's a solid chip for gaming and is excellent for multitasking. It suffers in comparison to the Intel Core 2 Duo E7400 when both are overclocked and you're throwing video encoding or image editing tasks their way, but that's not to say the X2 550 BE doesn't give the Intel CPU a good run for its money - if only it could roll over the 4GHz barrier!

If you're not into overclocking though, but fancy a fast machine for the family or friends, with the possibility of future upgrades; the 3.1GHz core clock affords a solid performance and the AM3 socket also has a bit of a future. It may not excel in very heavy workload - that's what quad cores are for - but for a basic all rounder, the Phenom II X2 550 Black Edition is certainly a good buy, and it's helped by the fact it's cheaper than comparable Intel chips, especially when you factor in platform costs.