AMD Phenom II X6 1075T, X4 970BE and Athlon II X4 645 processor review

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Athlon II X4 645 processor


Athlon II X4 645 processor

AMD a year ago brought the value targeted Athlon II processor to a quad-core package, and that's interesting alright as the fastest Athlon II quad core processor now runs at 3.1 GHz, at the cost of roughly 120 USD per processor, yeah... that's 30 USD per core.

What you'll notice with the Athlon II X4 processors is that the architecture (Propus core) shows a lot of similarities to Phenom II, and of course that was the building block for this somewhat cheaper design of processor. The biggest change is that 6MB Level 3 cache being cut away.

But let's walk through the Athlon II X4 architecture for a moment. Much like Phenom II, the Propus core inside the Athlon II X4 is made on a 45nm node. If you look at this from a distance it pretty much means that they were able to make this processor smaller compared to the last generation products. The die-size of this processor is now measuring only 169 mm².

A smaller fab size means advantages, often to be found in lower voltages and higher clock frequencies. The fastest Athlon II X4 was the 630, and ran at 2.8 GHz. The new 645 model runs a good 300 MHz faster at 3.1 GHz, with a full 2.0 GHz HT 3.0 speed. Voltage range is 0.925 to 1.425V. This processor generation has a slightly increased maximum peak wattage of 95 Watts (TDP). Being an AM3 package, the processor is both motherboard Socket AM2+ and AM3 compatible.

  • OPN: ADX645WFK42GM
  • L1 Cache Sizes: 64K of L1 instruction and 64K of L1 data cache per core (512KB total L1 per processor)
  • L2 Cache Sizes: 512KB of L2 data cache per core (2MB total L2 per processor)
  • Memory Controller Type: Integrated 128-bit wide memory controller
  • Memory Controller Speed: Up to 2.0GHz with Dual Dynamic Power Management
  • Types of Memory Supported: Unregistered DIMMs up to PC2-8500 (DDR2-1066MHz) -AND- PC3-10600 (DDR3-1333MHz)
  • HyperTransport 3.0 Specification: One 16-bit/16-bit link @ up to 4.0GHz full duplex (2.0GHz x2)
  • Total Processor-to-System Bandwidth: Up to 37.3GB/s total bandwidth [Up to 21.3 GB/s memory bandwidth (DDR3-1333) + 16.0GB/s (HT3)]
  • Up to 33.1GB/s total bandwidth [Up to 17.1 GB/s memory bandwidth (DDR2-1066) + 16.0GB/s (HT3)]
  • Packaging: Socket AM3 938-pin organic micro pin grid array (micro-PGA)
  • Fab location: GLOBALFOUNDARIES Fab 1 module 1 in Dresden, Germany
  • Process Technology: 45-nanometer DSL SOI (silicon-on-insulator) technology
  • Approximate Die Size: 169 mm2
  • Approximate Transistor count: ~300 million
  • Max TDP: 95 Watts
  • AMD Codename: Propus

This Athlon II X4 part is based on AMD's 45nm Silicon On Insulator process technology and has a total of 2MB L2 cache; 512KB per core. However -- a big change in Phenom II architecture was a large increase in L3 cache. Phenom II can address 6MB L3 cache shared among the cores as a buffer, so it can exchange data in-between the four logical cores. And it's exactly that part that has been stripped away from the Athlon II X4.

  • L1 Cache (Instruction + Data): 128KB x4 (64KB + 64KB for each core)
  • L2 Cache: 512KB x4 (quad-core)
  • L3 Cache: 6MB Shared L3

L3 is where a lot of the magic happens and is the reason for Phenom II's success. How much of an effect will this have on overall performance? Well, quite a bit really but that's what we'll find out in our benchmark session.

AMD Phenom II X4 920 and 940 testAthlon II X4 645 (Propus architecture) processor die

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