Athlon II X2 240

New Athlon II X2 processor models are based on one of three native core designs manufactured by AMD. First there is is Deneb, a Quad Core, that is implemented in all Phenom II models, with some variations to core number and L3 cache size. The second core is Propus, also with four logic cores, but no L3 cache. We reviewed an Athlon II X4 620 model a while back, and we have reviews of Athlon II X3 models planed in the near future, which are based on the same core design with one core disabled.

That brings us to the third and final core design. Cheapest, smallest and basic, the Regor with its two logic cores is implemented in all Athlon II X2 models and market entry Sempron models. All three cores are based on same K10.5 architecture, and the only real differences between them are the size of L2 and L3 cache memory. Deneb has 512 KB L2 cache per core and a large 6 MB L3 cache buffer that is shared between all cores. To make cheaper and slower models, Deneb, with some of its cores or some of its L3 cache memory disabled, were then renamed to Callisto/Heka and sent to market as Phenom II X2, X3 or X4 800 models. This is a great way to run a cost efficient production and offer a large selection of products to the customer.

It's the same story with the Propus core which is the base for Athlon II X4 processors. It also has 512 KB of L2 cache but lacks any L3 cache. This enables AMD to make small, power-efficient and cheap Quad Core processors, and if any of its logic cores is faulty - no problem, disable it and sell it as even cheaper Athlon II X3 (Rana) processor.
Finally there is the Regor core. It follows the same philosophy, but it has two logic cores, a total of 1 MB L2 cache memory per core, and no L3 cache memory.

To make the Regor core, AMD physically removed two cores from Propus (Quad Core). The resulting die area was so small that AMD had the opportunity to make some improvements while keeping the core die at a very cost efficient size. They increased the L2 cache from 512 KB to 1 MB per core. This means they nullified some of the performance impact of not having any L3 cache memory on board. Compared to L3 cache, L2 cache works at higher frequency, takes less cycles to process the instructions needed and has more bandwidth, so it should make some difference and we're going to check that out later in testing. In total, Regor's core die size measures 117 mm², not as small as Intel's Core 2 Duos but close enough.


Image courtesy of mAJORD from XtremeSystems.

Our Athlon II X2 240 works at 2.8 GHz frequency, 1.425 V stock voltage and has a 65 W TDP rating. For anyone who is familiar with AMD's current architecture this means three things: competitive price/performance ratio against Intel's Pentium processors, low heat output and great stock overclocking potential.

AMD is asking $60 for its Athlon II X2 240, and that's a fair deal right there. If you look at Intel's offering at that price point, Celeron E1600 and Pentiums E5x00 might just not be enough. When you put in play Athlon's flexibility with AM2+/AM3 and DDR2/DDR3 support plus all of the features it's packing including MMX, SSE2, SSE3, SSE4A instructions, Enhanced 3DNow!, NX bit, AMD64, Cool'n'Quiet, and AMD-V technology... it's clear that Intel needs something fresh in the lower market segments. Probably the most important feature is the AMD's virtualization technology, which Intel supports only with higher end Core 2 Duos and Core 2 Quad processors. Again, small business will love this feature at a $60 price point.

When talking about memory support, it's worth to note that the memory controller in Athlon II X2 models has beed downgraded to DDR2 1066 MHz and DDR3 1066 MHz, unlike other Athlon X3 and X4 models that support DDR3 up to 1333 MHz. But that's not a problem as you can manually get the memory to work up to 1600 MHz without a hitch. You may use the processor on either the AM3 or the older AM2+ platform, giving the opportunity for users to do a cheap update if they want to continue using their AM2/AM2+ motherboard and memory.

Overclocking is only possible by raising the HT Link frequency, as the multiplier is locked to 14x and can only be lowered.



It is clear that AMD is targeting non demanding users, or budget users if you like, with the new Athlon II X2 Series. It offers everything that the average user would ever want from a processor: low power consumption, low heat output, good performance and technology support and most important, cheap price. HTPC builders will rather choose the energy efficient "e" models of the Athlon II X2 or X3 lineup which were recently introduced. The normal version comes at higher voltage, resulting in higher power consumption, heat and cooler noise needed to disperse generated the heat. Gaming wise, it will be interesting to see how close the Athlon II X2 can get to AMD's Phenom II X2, which is a popular choice of some budget oriented gamers.

Like in our last review, we will be checking some non-standard features of AMD's Athlon II X2 240, including overclocking, reducing operational voltage and comparative performance to Phenom II Dual Core processor at the same clock speed.

Specifications

In the table below you can review detailed specifications of Athlon II X2 240 and other models that will show up later in the performance graphs. We will be using a clocked down 2.80 GHz Phenom II X2 to show the performance differences between Regor and Callisto cores at same frequencies. Intel is represented by two models in the similar price segment, Celeron E1600 and Pentium E5200. Core 2 Duo E8200 is included to compare Athlon II X2 240 performance to some higher end Intel Dual Core processors.