Touring the AMD 890FX Chipset and Athlon II 640 CPU

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This article is a quick precursor for our upcoming review of the ASUS Crosshair IV Formula, which houses AMD’s newest chipset, consisting of the 890FX northbridge and SB850 southbridge. The CPU used in that review will be AMD’s recently released Athlon II 640, so we’ll have a look at that too.

AMD’s 890 FX / SB850 Chipset

First, let’s have a look at what AMD’s newest chipset has to offer. Rather than jumping right into the details, let’s look at the handy-dandy architecture diagram and then some specification charts for the 8-series chipsets.

890 FX Architecture
890 FX Architecture

8-Series NB Specifications
8-Series NB Specifications

8-Series SB Specifications
8-Series SB Specifications

The only thing missing from the 890FX/SB850 chipset is the kitchen sink (and native USB 3.0, which can be added with a 3rd-party chip). Via the HyperTransport 3.0 link operating at 5.2GT/s, the 890FX northbridge supplies two full 16-lane graphics slots (or four 8x) for Crossfire GPU power (sorry, no SLI folks) as well as an extra 6 x1 and 1 x4 PCIe lanes for other peripherals.

The SB850 southbridge has native support for six SATA 6GB/s ports (if you didn’t know, that’s huge!), two extra PCIe x1 lanes and also handles HD Audio, Gigabit Ethernet, P-ATA and the PCI interface.

In case you noticed the big black IOMMU box in the picture, it’s helpful if you use virtual environments, allowing “virtual addressing of memory by system devices. This enables devices to use their native drivers in a virtualized environment for enhanced performance.”

Last, but certainly not least, AMD gives convenient software control of their chipset via their Overdrive utility. Of course “AMD product warranty does not cover damage caused by overclocking, even when enabled using AMD OverDrive™ software.” So there, you’ve been warned.

AMD Athlon II x4 640

In May, AMD not only released their top of the line powerhouses, the Phenom II x6’s (Thubans), they also released a sextet line of budget processors in the form of two each of Athlon II x2’s, x3’s and x4’s (code-name Propus).

Athlon II x4 Die Shot
Athlon II x4 Die Shot

The features list isn’t bad at all:

  • AMD delivers more choice and more compute-per-dollar in desktop computing, top-to-bottom
  • AMD holds ALL top Athlon price points stable while giving 100MHz more speed (this means price drops for existing models)
  • AMD’s sub-$100 quad becomes the Athlon II X4 635 (was the 630)
  • AMD’s ~$100 sub-45 watt triple core actually gains 200MHz (was 405e, now 415e)
  • New AMD processors are AM3/AM2+ compatible (single infrastructure = compatibility, flexibility and upgradability)
  • Any of these new parts make a good match for the recently released 800-series chipset-based motherboards
  • With our 800-series chipsets and new 6-core desktop CPUs launched, this Athlon II introduction rounds out AMD’s updated offerings for desktop computing
  • All the new processors being introduced are revision “C3” silicon

These are super-duper budget CPUs, which is an AMD specialty. They have always prided themselves as striving to be the price-to-performance kings. They not only improved the Athlon II line, they have given consumers an extra 100MHz for free! The new CPUs are priced very, very low for their technology. Here is the list of Athlon II’s released May 11th.

  • Athlon II X4 640 $122 (3.0GHz / 95W max TDP / 4 cores)
  • Athlon II X3 445 $87 (3.1GHz / 95W max TDP / 3 cores)
  • Athlon II X2 260 $76 (3.2GHz / 65W max TDP / 2 cores)
  • Athlon II X4 610e $143 (2.4GHz / 45W max TDP / 4 cores)
  • Athlon II X3 415e $102 (2.5GHz / 45W max TDP / 3 cores)
  • Athlon II X2 245e $77 (2.9GHz / 45W max TDP / 2 cores)

Go ahead, do a double-take; I certainly did. You really do see a quad-core CPU clocked at 3.0GHz with an MSRP of $122. Newegg lists them for $123.99, but that’s with free shipping. Give a little, take a little. By comparison, Intel’s least expensive quad-core, the Q8300, is clocked at 2.5GHz and sells for $148.99. Jumping up to the least expensive iX quad, the i5 750 will set you back $199.99.

Athlon II x4 640
Athlon II x4 640

This 3.0Ghz Athlon II 640 is the CPU we’ll be looking at along with the Crosshair IV Formula. Here are its detailed specifications:

AMD Athlon II™ X4 640 Processor Specifications:

  • Model Number, Core Frequency & Price: X4 640 / 3.0GHz
  • Tray OPNs: ADX640WFK42GM
  • 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 Temp: 71o Celsius
  • Nominal Voltage: 1.05-1.4V
  • Max TDP: 95 Watts
  • AMD Codename: “Propus”

*Note: configurable for dual 64-bit channels for simultaneous read/writes

One thing you’ll notice in these specifications is their lack of L3 cache that the Athlon II’s big brothers, the Phenom II’s have. A good thing to note is in the features list from earlier – all of these new Athlon II’s are revision C3 silicon, meaning they support hardware initiated C1E, northbridge p-states (another power-saving feature) and low-voltage (1.35V) DDR3 support up to 1067MT/s.

That’s it for this one folks…just wanted to wet your whistle in anticipation of the review that will be coming out soon. Hope you’ll join us for that one!

Jeremy Vaughan (hokiealumnus)

About Jeremy Vaughan 197 Articles
I'm an editor and writer here at as well as a moderator at our beloved forums. I've been around the overclocking community for several years and just love to sink my teeth into any hardware I can get my paws on!


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  1. Thanks! Do you mean a photo of the chip itself? I have one in the Crosshair IV Formula review. :)
    Pushing like heck to get it out tomorrow, but Monday is looking more and more likely. We'll see!
    That too! But, no, I've had trouble finding the block diagram for the 890FX instead of the GX. Maybe I just haven't been looking in the right places ... :shrug: