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Platform Support For FX: Make Sure It’s AM3+

AMD Bulldozer Review: FX-8150 Gets Tested
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When AMD launched its 990FX chipset (The 990FX Chipset Arrives: AMD And SLI Rise Again), there wasn’t much new to report aside from Socket AM3+ and Nvidia SLI support. But pushing out a platform update ahead of FX’s launch wasn’t a bad idea. After all, existing Socket AM3-compatible CPUs could easily drop into the 990FX-based motherboards, establishing a foundation for Socket AM3+ FX processors.

From my 990FX platform review: "You need the 942-pin Socket AM3+ (AM3b) interface, though, in order to support Zambezi’s power and frequency management features."

If you already own a Socket AM3+-equipped board, you need to flash its firmware with a Socket AM3-based processor installed before upgrading to an FX CPU. The firmware updates AMD’s AGESA (AMD Generic Encapsulated Software Architecture) to support the Bulldozer architecture.

Enthusiasts still running previous-generation Thuban- or Deneb-based Phenom IIs may not want to adopt these FX-enabling BIOS updates. We hear from the motherboard vendors that the performance of an older processor could be negatively affected by extensive changes made to the AGESA.

FX processors will not work in an AM3-based board. AMD deliberately blocked that combination out in its BIOS. Now, what if you’re rocking an 890FX-based motherboard with a Socket AM3+ interface? AMD isn’t explicitly supporting such a configuration, though Socket AM3+/890FX boards do exist. Compatibility could be a roll of the dice, but there isn't any specific reason a vendor claiming interoperability can't achieve it.

In addition to the 990FX chipset, AMD also supports Zambezi-based FX processors with its 990X and 970 chipsets. Of course, 990FX supports as many as four graphics cards through a 4 x 8-lane PCI Express 2.0 configuration (or you can do two true x16 slots). AMD’s 990X does up to two discrete cards through a pair of x8 slots (or one card in a x16 slot). Going the 970 route caps you at a single x16 slot for graphics; CrossFire simply is not supported on that platform.

Because AMD designs its own CPUs, chipsets, and graphics cards, it’s able to build complete platforms. Two years ago, the company’s Dragon platform included Socket AM2/AM2+ Phenom II processors, the 790 chipset, and Radeon HD 4000-series GPUs. Last year, Leo added the Socket AM3-based Phenom IIs, its 890-series chipsets, and Radeon HD 5000-series cards. In 2011, Scorpius centers on an AM3+-based FX, any of those three 900-series chipsets, and a Radeon HD 6000 add-in board.

On Unlocking Cores

All seven of the Zambezi-based FX processors employ the same silicon. Some of the processors have one Bulldozer module disabled, and some have two turned off. Seemingly, that’d set us up for the same sort of situation we saw when I got my hands on AMD’s quad-core Zosma processor, where a quad-core chip based on a hexa-core die could be unlocked to enable all six cores. Apparently, AMD says that won’t happen this time around. The company claims to have disabled the way in which this might have been possible. It's instead cranking up the clocks on SKUs with fewer cores, Turning on that disabled logic could cause stability issues.

With all of that said, we heard that core unlocking wasn’t possible a couple of years ago. And yet, we still managed to get several Phenom II X3s unlocked. We won’t close the door on the FX until motherboard vendors start confirming they can’t take a, say, FX-4100 up to something similar to an -8150.

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  • 54 Hide
    Homeboy2 , October 12, 2011 4:38 AM
    killerclickAs I said before, it won't come close to beating Intel in performance or price. Now let's hear the fanboys whine.


    Everyone should cry, even the Intel fanboys, this is bad news for everyone, now Intel has absolutely no incentive to lower prices or accelerate Ivy Bridge.
  • 51 Hide
    jdwii , October 12, 2011 4:14 AM
    Been so long and i'm kinda sad.
  • 47 Hide
    gmcizzle , October 12, 2011 4:25 AM
    What I learned: the 2.5 year old i7-920 is still a beast.
Other Comments
  • 51 Hide
    jdwii , October 12, 2011 4:14 AM
    Been so long and i'm kinda sad.
  • 43 Hide
    compton , October 12, 2011 4:16 AM
    Not many surprises but I've been waiting for a long, long time for this. I hope this is just the first step to a more competitive AMD.
  • 29 Hide
    ghnader hsmithot , October 12, 2011 4:16 AM
    At least its almost as good as Nehalem.
  • 40 Hide
    gamerk316 , October 12, 2011 4:17 AM
    Dissapointing. Predicted it ages ago though. PII X6 is a better value.
  • 26 Hide
    Anonymous , October 12, 2011 4:18 AM
    As I expected - failure.
  • 25 Hide
    AbdullahG , October 12, 2011 4:18 AM
    I see the guys from the BD Rumors are here. As many others are, I'm disappointed.
  • 33 Hide
    iam2thecrowe , October 12, 2011 4:20 AM
    for the gaming community this is a FLOP.
  • 25 Hide
    phump , October 12, 2011 4:22 AM
    FX-4100 looks like a good alternative to the 955BE. Same price, higher clock, and lower power profile.
  • 40 Hide
    phatbuddha79 , October 12, 2011 4:25 AM
    Why bring back the FX brand for something like this?
  • 47 Hide
    gmcizzle , October 12, 2011 4:25 AM
    What I learned: the 2.5 year old i7-920 is still a beast.
  • 25 Hide
    Ragnar-Kon , October 12, 2011 4:36 AM
    Looks like solid chips, but I'll admit that the price point isn't low enough to compete in the gaming world with Intel.

    I am rather curious how the FX-4100 will stack up against the current Phenom II X4 chips.

    And even though the FX is a slight disappointment, I am rather impressed by the Windows 8 benchmarks. Having said that, by the time Windows 8 is ready for release I'm sure Intel will have an even better solution.
  • 25 Hide
    Tamz_msc , October 12, 2011 4:37 AM
    So Bulldozer is AMD's version of NetBurst?
  • 54 Hide
    Homeboy2 , October 12, 2011 4:38 AM
    killerclickAs I said before, it won't come close to beating Intel in performance or price. Now let's hear the fanboys whine.


    Everyone should cry, even the Intel fanboys, this is bad news for everyone, now Intel has absolutely no incentive to lower prices or accelerate Ivy Bridge.
  • 12 Hide
    the associate , October 12, 2011 4:41 AM
    killerclickAs I said before, it won't come close to beating Intel in performance or price. Now let's hear the fanboys whine.


    Waaaahhhhhhhhhhhhh!!!!!!!!

    Bah, well, been with AMD since my first pc like 8 years ago...Guess I'll be going intel for the first time ever especially since I can get an overkill cpu for just 300 bucks. Hell that's how much I payed for my phenom II 955...
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