After conquering the $100 price segment, AMD is introducing a cut down version of their Athlon II X4 processors to fill up the performance and price gap between entry level dual core models and recently introduced Athlon II X4 Quad Core processors. AMD's new Athlon II X3 Series, like its name suggests, is equipped with three logic cores, and is based on AMD's K10.5 architecture, like any other Athlon II or Phenom model.
The Athlon II X3 425 model we're reviewing today shares a lot of similarities with Athlon II X4 models, because it is based on a Propus Quad Core with one disabled core. Thus, the Rana core is born, at least on paper and yes, it is possible for the fourth core to be unlocked. Athlon II X3 425 is the cheapest, and slowest version (not including the energy efficient "e" models) working at 2.70 GHz, and with its affordable price tag of just $79, it threatens Intel's new Pentium models.
I would like to thank Links for providing the processor sample for this review.
Packaging and Contents
The Athlon II X3 425 comes in a retail package that includes a short installation manual, AMD Athlon II X3 case-badge, AMD-certified aluminum heatsink, and of course the processor itself. AMD offers a 3-year warranty for all retail processors, including this one.
Athlon II X3 425
If you read our Athlon II X4 620 review published recently, everything you've read there applies here as well. Athlon II X3 series, with one disabled core, is the Athlon II X4 processor. It's based on same Propus core like Athlon II X4, but because one core is disabled, AMD renamed it to Rana. No other modifications or changes have been done, so like Athlon II X4 it supports AM2+ and AM3 sockets, as well as DDR2 up to 1066 MHz and DDR3 memory up to 1333 MHz.
The Athlon II X3 425 is clocked at 2.70 GHz which puts it ahead of the Athlon II X4 620 by 100 MHz, and makes it 200 MHz slower than the fastest Dual Core Athlon II X2 250. Considering it has three cores and a price tag of $79, this sounds like a real sweet spot for a budget CPU. AMD has set a very high operational voltage of 1.425 for this processor, just like with the Athlon II X4 series, which results in higher power consumption and more heat output. But for some overclockers this could also mean higher overclocking potential with stock voltage. The TDP rating for Athlon II X3 models is set to 95W, same as on the Quad Core Athlon II models. Of course, I will be checking undervolting capabilities of Athlon II X3 425, as well as unlocking options.
Since the Athlon II X3 series is based on a Propus-derived Rana core, it is missing the L3 cache and has just 512 KB of L2 cache memory per core. This will have a serious impact on performance in some benchmarks, with gaming taking the biggest hit. By removing the L3 cache memory, AMD significantly reduced the core die size which measures 168 mm². A smaller die means lower manufacturing costs, which results in lower prices for end customers. But by removing the L3 cache, AMD also removed one of the most important features of the K10.5 architecture: its large and fast memory buffer for CPU instructions which can be shared between all cores. Without L3 cache, the CPU cores have to wait for instructions from much slower system memory, resulting in performance drops in some applications. Performance scaling is also weakened, because no matter how fast the CPU is clocked, it still has to wait for instructions from system memory to process any fast clocked workload.
Athlon II X3 425 is connected to the rest of your PC components through Northbridge via HyperTransport interconnect which provides up to 16 GB/s bandwidth. More than enough bandwidth even for quad CrossFireX setups.
As far as other technology implementations go, there are no changes compared to AMD's Athlon II X4 series, which means Athlon II X3 is supporting everything that the top model Phenoms support, including MMX, SSE2, SSE3, SSE4A instructions, Enhanced 3DNow!, NX bit, AMD64, Cool'n'Quiet, and AMD-V virtualization technology.
If you are thinking about overclocking, it is recommended to have decent memory and motherboard as the multiplier is locked to 13.5, and overclocking must be done via increasing the HT Link value.
Specifications
In the table below you can review detailed specifications of Athlon II X3 425 and other models that will show up later in the performance graphs. Intel's closest price competitor is the new Pentium E6x00 series, to be exact, the Pentium E6300 Dual Core model clocked at 2.8 GHz.